Improve PHPCS caching

[desrosj]

In the coding standards GitHub Action workflow, the cache file produced by PHPCS is stored as a GHA cache to speed up runs on successive workflows.

This greatly decreases the time required to run scans when the cache file is present. But, because there are two different scans run and only one cache file is stored, the cache is likely not as efficient as it could be.

See the ​discussion on GitHub where this ticket was spawned from.

Create separate caches for the PHPCS src run and the PHPCS tests run and save both to the GHA cache.

Refs:

• ​https://github.com/squizlabs/PHP_CodeSniffer/wiki/Usage
• ​https://github.com/actions/cache#usage

Trac ticket: https://core.trac.wordpress.org/ticket/57148

Create separate caches for the PHPCS src run and the PHPCS tests run and save both to the GHA cache.

Refs:

• ​https://github.com/squizlabs/PHP_CodeSniffer/wiki/Usage
• ​https://github.com/actions/cache#usage

Trac ticket: https://core.trac.wordpress.org/ticket/57148

[jrf]

PR ​GH #3650 addresses this.

Just a note about a thought I had. At first I considered suggesting we remove the <arg name="cache"> from phpcs.xml.dist, but I think it makes sense to leave that as that cache works for anyone running PHPCS commands locally.

Exactly. Sorry, I should have mentioned that in the PR description (cause I did the same thought exercise when creating the patch).

[desrosj]

In 54921:

Build/Test Tools: Improve caching for PHPCS.

This improves the speed of the PHPCS scans between workflow runs in GitHub Action by creating a scan cache file for each unique set of arguments passed to phpcs.

Props jrf.
Fixes #57148. See #53841.

Closing as merged via https://core.trac.wordpress.org/changeset/54921