Tests: Disable PHP version check until PHP 8.0 compatibility is achieved.

[costdev]

• PHP 7.4 is ​no longer displayed as a stable version.
• The next stable version is PHP 8.0, which we're not compatible with yet.
• PHP 7.4's change from stable to security is causing a ​PHPUnit test failure in Tests_External_HTTP_Basic::test_readme().

If no discussions or decisions have been made on this yet, I suggest that we disable the failing assertion in this test method until we either:

• Reach PHP 8.0 compatibility and bump the recommended PHP version in src/readme.html.
• Refactor this part of the test method.
• Make another decision about this.

[costdev]

Disables the failing assertion.

[audrasjb]

Thanks for the ticket and patch.
Indeed, we need to disable that unit test otherwise it will throw errors on each commit.

[SergeyBiryukov]

In 52260:

Tests: Temporarily disable the check that the current recommended PHP version is actively supported.

As PHP 7.4 moved from active support to security support until 28 Nov 2022, and no discussions or decisions have been made yet on bumping the recommended version to PHP 8.0, this commit disables the failing assertion for now.

This should be revisited once WordPress achieves PHP 8.0 compatibility and the recommended PHP version in readme.html can be bumped, or another decision is made about this.

Follow-up to [26166], [33937], [33944], [33946], [35172], [39582], [39583], [40241], [46682], [46996], [46998].

Props costdev, audrasjb.
Fixes #54528.