Prevent PHPUnit tests from running on `push` for forks and private mirrors

[desrosj]

In [50441], the PHPUnit workflow was updated to allow WordPress to be run from src. The workflow was reorganized to take advantage of this change, but it has resulted in unnecessary workflow runs on forks and private mirrors.

Before [50441], the first job (which built and prepared WordPress for testing) was required to complete before the second one (that performed all the actual testing) could take place. Because the first job now only cancels incomplete workflow runs in pull requests, the testing job runs always.

This can be fixed with an if: statement to ensure the jobs only run in the correct context.

[desrosj]

This will need to be backported back to the 5.2 branch.

[desrosj]

This was fixed in [50670], but appears Trac is currently having issues with that commit. The next commit should fix that.

[desrosj]

In 50671:

Build/Test Tools: Prevent PHPUnit tests on push for forks/private mirrors.

The reorganization of the PHPUnit workflow in [50441] unintentionally caused the tests to be run for every push event, even for forks and private mirrors.

Previously, the second job required the first one to pass, and the conditional check on the first prevented both from running. Because the first job is no longer required for the second, both jobs must have the appropriate conditional check.

Merges [50670] to the 5.7 branch.
Fixes #52983.

[desrosj]

In 50672:

Build/Test Tools: Prevent PHPUnit tests on push for forks/private mirrors.

The reorganization of the PHPUnit workflow in [50441] unintentionally caused the tests to be run for every push event, even for forks and private mirrors.

Previously, the second job required the first one to pass, and the conditional check on the first prevented both from running. Because the first job is no longer required for the second, both jobs must have the appropriate conditional check.

Merges [50670] to the 5.6 branch.
Fixes #52983.

[desrosj]

In 50673:

Build/Test Tools: Prevent PHPUnit tests on push for forks/private mirrors.

The reorganization of the PHPUnit workflow in [50441] unintentionally caused the tests to be run for every push event, even for forks and private mirrors.

Previously, the second job required the first one to pass, and the conditional check on the first prevented both from running. Because the first job is no longer required for the second, both jobs must have the appropriate conditional check.

Merges [50670] to the 5.5 branch.
Fixes #52983.

[desrosj]

In 50674:

Build/Test Tools: Prevent PHPUnit tests on push for forks/private mirrors.

The reorganization of the PHPUnit workflow in [50441] unintentionally caused the tests to be run for every push event, even for forks and private mirrors.

Previously, the second job required the first one to pass, and the conditional check on the first prevented both from running. Because the first job is no longer required for the second, both jobs must have the appropriate conditional check.

Merges [50670] to the 5.4 branch.
Fixes #52983.

[desrosj]

In 50675:

Build/Test Tools: Prevent PHPUnit tests on push for forks/private mirrors.

The reorganization of the PHPUnit workflow in [50441] unintentionally caused the tests to be run for every push event, even for forks and private mirrors.

Previously, the second job required the first one to pass, and the conditional check on the first prevented both from running. Because the first job is no longer required for the second, both jobs must have the appropriate conditional check.

Merges [50670] to the 5.3 branch.
Fixes #52983.

[desrosj]

In 50676:

Build/Test Tools: Prevent PHPUnit tests on push for forks/private mirrors.

The reorganization of the PHPUnit workflow in [50441] unintentionally caused the tests to be run for every push event, even for forks and private mirrors.

Previously, the second job required the first one to pass, and the conditional check on the first prevented both from running. Because the first job is no longer required for the second, both jobs must have the appropriate conditional check.

Merges [50670] to the 5.2 branch.
Fixes #52983.