Update GitHub-hosted runners to `ubuntu-26.04`

[desrosj]

After ​making the Ubuntu 26.04 runner image generally available on 2026-09-17, GitHub is in the process of gradually moving the ubuntu-latest label from Ubuntu 24.04 to 26.04 (​actions/runner-images#14748).

While workflow files currently explicitly pin ubuntu-24.04, fewer runner images will be available once the transition completes and eventually that image will be retired.

Workflow files should be updated to using the new ubuntu-26.04 runners instead.

Some notes:

• While branches >=6.8 currently pin ubuntu-24.04 explicitly, older ones use ubuntu-latest. This should be changed
• Playwright will need to be updated in older branches to ensure the required dependencies support 26.04. Versions 1.50.0 through 1.60.x identify Ubuntu 26.04 as ubuntu26.04-x64, but has no browser downloads for that platform and fail to install. 1.61.0 is the first version that supports Ubuntu 26.04. Branches 6.4 through 6.7 use 1.49.1, which falls back to the 24.04 browser build and works on 26.04. If possible, they should be updated anyway for consistency.

The ubuntu-26.04 runner image is ​now generally available, and ubuntu-latest is moving from 24.04 to 26.04 between 2026-10-19 and 2026-11-19 (tracked in actions/runner-images#14748).

This PR updates every workflow and reusable workflow that currently pins ubuntu-24.04 to use ubuntu-26.04 instead (43 files, including the default os input on the reusable workflows).

Also:

• The pinned actionlint version (v1.7.11) does not recognize the ubuntu-26.04 label yet, so it is temporarily registered in .github/actionlint.yaml.
• Updated the comment above the AppArmor workaround in reusable-javascript-tests.yml so it no longer refers only to 24.04.

Note: the versioned reusable workflows (-v1, -v2, and so on) are also called from older branches. Changing their default os input will move those branches to 26.04 too, unless they pass os explicitly.

This is a draft while the workflow results are reviewed.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label replacement and the actionlint config change, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

Backport of the runner update in #15518 to the 6.3 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

The 6.3 branch's full CI was run on ubuntu-26.04 in my fork (desrosj/wordpress-develop#661), including Puppeteer-based E2E and QUnit tests: all checks passed.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.2 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.1 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.0 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.9 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

The 5.9 branch's full CI was run on ubuntu-26.04 in my fork (desrosj/wordpress-develop#660), including Puppeteer-based E2E and QUnit tests: all checks passed.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.8 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.7 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.6 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.5 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.4 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.3 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.2 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.1 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 5.0 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 4.9 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 4.8 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

Branches 4.7, 5.9, and 6.3 were run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659, #660, #661), covering every Puppeteer/Node 14 tooling generation used from 4.7 to 6.3: all checks passed. This branch uses the same tooling as its neighbours.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 4.7 branch.

This changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19, so this pins the version explicitly, matching trunk. Only Ubuntu labels are changed; windows-latest and macos-latest are untouched.

The jobs defined in this branch's own workflow files are mostly housekeeping (Failed workflow tasks, the welcome message). The os matrix values passed to reusable workflows (PHPUnit, build process testing) are also updated. Jobs that call reusable workflows from trunk without an os input (JavaScript tests, E2E, coding standards, PHP compatibility) will move to 26.04 when #15518 is merged.

This branch does not use Playwright, so no dependency changes are needed.

Testing

The 4.7 branch's full CI was run on ubuntu-26.04 in my fork (desrosj/wordpress-develop#659), including QUnit tests with Puppeteer 4.0.1 and the AppArmor workaround: all checks passed.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made the label changes, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 7.1 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-24.04 to ubuntu-26.04. GitHub is moving ubuntu-latest to 26.04 between 2026-10-19 and 2026-11-19, and 26.04 is the newest GA image.
• Adds .github/actionlint.yaml registering the ubuntu-26.04 label. The pinned actionlint version (1.7.11) does not recognize it yet and would fail with label "ubuntu-26.04" is unknown. This can be removed once actionlint is updated.
• Updates @playwright/test from 1.61.1 to 1.64.1, matching trunk. 1.61.1 already supports Ubuntu 26.04, so on this branch this is only to stay consistent with trunk and the other branches. Playwright 1.50.0–1.60.x fail on 26.04 with ERROR: Playwright does not support chromium on ubuntu26.04-x64, which is why older branches need the update.

The Playwright changes are in their own commit so they can be reviewed or dropped separately.

Playwright 1.61.1 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and playwright-core change, each to 1.64.1. There is a single playwright-core copy, and nothing else depends on an older Playwright.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Test discovery: playwright test --list finds the same tests before and after the update for every config, with no warnings: e2e 27, performance 720, visual-regression 22.
• API changes: none of the changes in the 1.62–1.64 release notes affect this branch. That covers removed APIs, the 1.64 screen forwarding from devices['Desktop Chrome'], hidden-iframe visibility, and JSX/tsconfig handling.

Testing

actionlint passes locally with the new config.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.9 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-24.04 to ubuntu-26.04, matching trunk. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19.
• Adds .github/actionlint.yaml registering the ubuntu-26.04 label. The pinned actionlint version (1.7.11) does not recognize it yet and would fail with label "ubuntu-26.04" is unknown. This can be removed once actionlint is updated.
• Updates @playwright/test from 1.56.1 to 1.64.1, matching trunk. This update is required on this branch. Playwright 1.50.0–1.60.x fail on Ubuntu 26.04 with ERROR: Playwright does not support chromium on ubuntu26.04-x64, and 1.61.0 is the first version that supports it. This branch's E2E and performance tests run through reusable workflows from trunk, so they break as soon as trunk's reusable workflows move to 26.04 (#15518).

The Playwright changes are in their own commit so they can be reviewed separately.

Playwright 1.56.1 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and playwright-core change, each to 1.64.1. There are no nested or duplicate copies. @wordpress/scripts 30.26.2 has peer ^1.55.0, which 1.64.1 satisfies.
• Test discovery: playwright test --list output is identical before and after: e2e 25, performance 720, visual-regression 22.
• API changes: none of the removed or changed APIs in the 1.57–1.64 release notes are used (including page.accessibility, removed in 1.57). The custom performance reporter only uses onTestEnd/onEnd.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Visual changes: 1.64 forwards the 1920×1080 screen from devices['Desktop Chrome'] in the @wordpress/scripts base config, and 1.57 switched Chromium to Chrome for Testing builds. Either could change toHaveScreenshot output, but the visual regression suite isn't run in CI and has no committed baselines. If the old screen behaviour is needed, add screen: undefined to the config's use.

Testing

The 6.8 branch (desrosj/wordpress-develop#666) and 7.0 branch (desrosj/wordpress-develop#667) with the same update passed E2E and performance on ubuntu-26.04 in my fork. This branch hasn't been run on 26.04 yet, so its E2E and performance workflows should be run before merging.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.8 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-24.04 to ubuntu-26.04, matching trunk. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19.
• Adds .github/actionlint.yaml registering the ubuntu-26.04 label. The pinned actionlint version (1.7.11) does not recognize it yet and would fail with label "ubuntu-26.04" is unknown. This can be removed once actionlint is updated.
• Updates @playwright/test from 1.50.1 to 1.64.1, matching trunk. This update is required on this branch. Playwright 1.50.0–1.60.x fail on Ubuntu 26.04 with ERROR: Playwright does not support chromium on ubuntu26.04-x64, and 1.61.0 is the first version that supports it. This branch's E2E and performance tests run through reusable workflows from trunk, so they break as soon as trunk's reusable workflows move to 26.04 (#15518).

The Playwright changes are in their own commit so they can be reviewed separately.

Playwright 1.50.1 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and playwright-core change, each to 1.64.1. There are no nested or duplicate copies.
• Test discovery: playwright test --list output is identical before and after: e2e 25, performance 720, visual-regression 22.
• API changes: none of the removed or changed APIs in the 1.51–1.64 release notes are used. The test.use in the application passwords tests defines a new fixture rather than overriding a built-in one, so the 1.60 fixture-override error doesn't apply.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Visual changes: 1.64 forwards the 1920×1080 screen from devices['Desktop Chrome'] in the @wordpress/scripts base config, and 1.57 switched Chromium to Chrome for Testing builds. Either could change toHaveScreenshot output, but the visual regression suite isn't run in CI and has no committed baselines. If the old screen behaviour is needed, add screen: undefined to the config's use.

Testing

Run in full on ubuntu-26.04 in my fork:

• With 1.50.1 (desrosj/wordpress-develop#662): both E2E jobs and all four performance jobs failed with the unsupported-platform error.
• With 1.64.1 (desrosj/wordpress-develop#666): both E2E jobs passed, 23 of 25 tests passing outright. The other 2 (install.test.js:34, media-upload.test.js:11) were flaky but passed on retry, and are already flaky on upstream 6.8 with 24.04 and 1.50.1. All four performance jobs passed, 720/720 tests each, in roughly half the wall time.

Expect a step change in the absolute performance metrics reported to the dashboard.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.6 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04, matching trunk. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19.
• Updates @playwright/test from 1.49.1 to 1.64.1, matching trunk. 1.49.1 still works on Ubuntu 26.04 (it falls back to the 24.04 browser build), so this is not required on this branch. It keeps a single Playwright version across trunk and all branches that use it.

The Playwright changes are in their own commit so they can be reviewed separately.

Playwright 1.49.1 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and playwright-core change, each to 1.64.1. The diff is larger than on 6.7+ because this branch uses lockfileVersion: 2, which lists each package twice. There is a single playwright-core copy after install.
• Test discovery: playwright test --list finds the same tests before and after: e2e 24, performance 320, visual-regression 22.
• API changes: none of the removed or changed APIs in the 1.50–1.64 release notes are used.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Visual changes: 1.64 forwards the 1920×1080 screen from devices['Desktop Chrome'] in the @wordpress/scripts base config, and 1.57 switched Chromium to Chrome for Testing builds. Either could change toHaveScreenshot output, but the visual regression suite isn't run in CI and has no committed baselines. If the old screen behaviour is needed, add screen: undefined to the config's use.

Testing

The 6.4 branch (desrosj/wordpress-develop#665) and 6.8 branch (desrosj/wordpress-develop#666) with the same update passed on ubuntu-26.04 in my fork. This branch hasn't been run on 26.04 yet.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.5 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04, matching trunk. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19.
• Updates @playwright/test from 1.49.1 to 1.64.1, matching trunk. 1.49.1 still works on Ubuntu 26.04 (it falls back to the 24.04 browser build), so this is not required on this branch. It keeps a single Playwright version across trunk and all branches that use it.

The Playwright changes are in their own commit so they can be reviewed separately.

Playwright 1.49.1 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and playwright-core change, each to 1.64.1, and no 1.49.1 copy is left.
• Older copy: @wordpress/scripts 27.2.6 still pins playwright-core 1.39.0. It only uses it to install browsers when PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD is unset, and the E2E workflow sets that variable, so it never runs in CI.
• Test discovery: playwright test --list output is identical before and after: e2e 21, performance 120, visual-regression 22.
• API changes: none of the removed or changed APIs in the 1.50–1.64 release notes are used. The editor test's frameLocator('[name=editor-canvas]') points at a visible iframe, so 1.64's hidden-iframe change doesn't apply.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Visual changes: 1.64 forwards the 1920×1080 screen from devices['Desktop Chrome'] in the @wordpress/scripts base config, and 1.57 switched Chromium to Chrome for Testing builds. Either could change toHaveScreenshot output, but the visual regression suite isn't run in CI and has no committed baselines. If the old screen behaviour is needed, add screen: undefined to the config's use.

Testing

The neighbouring 6.4 branch with the same update passed all checks on ubuntu-26.04 in my fork (desrosj/wordpress-develop#665). This branch hasn't been run on 26.04 yet.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.4 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04, matching trunk. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19.
• Updates @playwright/test from 1.49.1 to 1.64.1, matching trunk. 1.49.1 still works on Ubuntu 26.04 (it falls back to the 24.04 browser build), so this is not required on this branch. It keeps a single Playwright version across trunk and all branches that use it.

The Playwright changes are in their own commit so they can be reviewed separately.

Playwright 1.49.1 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and the playwright-core copy nested under playwright change, each to 1.64.1. Nothing else moves.
• Older copy: @wordpress/scripts 26.13.13 still depends directly on playwright-core 1.32.0. wp-scripts test-playwright only uses that copy to install browsers before the run; the tests run on 1.64.1. This was already the case with 1.49.1, so it isn't a regression.
• Test discovery: playwright test --list finds the same tests before and after: e2e 20, performance 40, visual-regression 22.
• API changes: none of the removed or changed APIs in the 1.50–1.64 release notes are used by this branch's tests, its configs, or @wordpress/e2e-test-utils-playwright 0.10.13.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Visual changes: 1.64 forwards the 1920×1080 screen from devices['Desktop Chrome'] in the @wordpress/scripts base config, and 1.57 switched Chromium to Chrome for Testing builds. Either could change toHaveScreenshot output, but the visual regression suite isn't run in CI and has no committed baselines. If the old screen behaviour is needed, add screen: undefined to the config's use.

Testing

This exact lockfile was run in full on ubuntu-26.04 in my fork (desrosj/wordpress-develop#665): all 46 checks passed, with 20/20 E2E tests passing and none flaky, retried, or skipped. That matches the same branch on 1.49.1 (desrosj/wordpress-develop#664) and on 24.04 upstream.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 7.0 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-24.04 to ubuntu-26.04, matching trunk. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19.
• Adds .github/actionlint.yaml registering the ubuntu-26.04 label. The pinned actionlint version (1.7.11) does not recognize it yet and would fail with label "ubuntu-26.04" is unknown. This can be removed once actionlint is updated.
• Updates @playwright/test from 1.58.2 to 1.64.1, matching trunk. This update is required on this branch. Playwright 1.50.0–1.60.x fail on Ubuntu 26.04 with ERROR: Playwright does not support chromium on ubuntu26.04-x64, and 1.61.0 is the first version that supports it. This branch's E2E and performance tests run through reusable workflows from trunk, so they break as soon as trunk's reusable workflows move to 26.04 (#15518).

The Playwright changes are in their own commit so they can be reviewed separately.

Playwright 1.58.2 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and playwright-core change, each to 1.64.1. There are no nested or duplicate copies.
• Test discovery: playwright test --list output is identical before and after: e2e 25, performance 720, visual-regression 22.
• API changes: none of the removed or changed APIs in the 1.59–1.64 release notes are used by the tests, configs, @wordpress/scripts, or @wordpress/e2e-test-utils-playwright 1.42.0.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Visual changes: 1.64 forwards the 1920×1080 screen from devices['Desktop Chrome'] in the @wordpress/scripts base config, and 1.57 switched Chromium to Chrome for Testing builds. Either could change toHaveScreenshot output, but the visual regression suite isn't run in CI and has no committed baselines. If the old screen behaviour is needed, add screen: undefined to the config's use.

Testing

Run in full on ubuntu-26.04 in my fork:

• With 1.58.2 (desrosj/wordpress-develop#663): both E2E jobs and all four performance jobs failed with the unsupported-platform error.
• With 1.64.1 (desrosj/wordpress-develop#667): one E2E job passed 25/25. The other passed 24, with install.test.js:34 flaky but passing on retry. That test is already flaky upstream: a recent upstream 7.0 run on 24.04 had two flaky tests in each job. All four performance jobs passed; the two sampled had 720/720 tests passing.

Expect a step change in the absolute performance metrics reported to the dashboard.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH

Backport of the runner update in #15518 to the 6.7 branch.

Changes

• Changes the GitHub-hosted Ubuntu runners used by this branch's workflows from ubuntu-latest to ubuntu-26.04, matching trunk. GitHub is moving ubuntu-latest from 24.04 to 26.04 between 2026-10-19 and 2026-11-19.
• Updates @playwright/test from 1.49.1 to 1.64.1, matching trunk. 1.49.1 still works on Ubuntu 26.04 (it falls back to the 24.04 browser build), so this is not required on this branch. It keeps a single Playwright version across trunk and all branches that use it.

The Playwright changes are in their own commit so they can be reviewed separately.

Playwright 1.49.1 → 1.64.1 review

• Lockfile: only @playwright/test, playwright and playwright-core change, each to 1.64.1. There is a single playwright-core copy, and @wordpress/scripts 30.0.6 does not pin one of its own.
• Test discovery: playwright test --list output is identical before and after: e2e 23, performance 320, visual-regression 22.
• API changes: none of the removed or changed APIs in the 1.50–1.64 release notes are used (including page.accessibility and page.route globs). The clipboard helper fakes paste events in the page rather than using the OS clipboard.
• Requirements: 1.64.1 requires Node >=20, and this branch uses Node 20.
• Visual changes: 1.64 forwards the 1920×1080 screen from devices['Desktop Chrome'] in the @wordpress/scripts base config, and 1.57 switched Chromium to Chrome for Testing builds. Either could change toHaveScreenshot output, but the visual regression suite isn't run in CI and has no committed baselines. If the old screen behaviour is needed, add screen: undefined to the config's use.

Testing

The 6.4 branch (desrosj/wordpress-develop#665) and 6.8 branch (desrosj/wordpress-develop#666) with the same update passed on ubuntu-26.04 in my fork. This branch hasn't been run on 26.04 yet.

Trac ticket: Core-66499

Use of AI Tools

Claude Code (Claude Opus 5.5) made these changes, reviewed the Playwright update, ran the fork-based test runs, and drafted this description. All changes need to be reviewed by a human before this is marked ready for review.

🤖 Generated with ​Claude Code

​https://claude.ai/code/session_011Y86gzNmrCaBaUCqQTNKYH