Description of the Change

This PR updates our PHPCS testing to ensure we run PHP compat tests on PHP 7.0+, hopefully flagging any issues with code that isn't compliant with our minimums. It also updates our PHPUnit tests to run on all PHP versions from 7.0 to 8.1, again hopefully catching issues that don't match our supported versions.

Note: the PHPCompatibility tool does not yet fully support PHP 8. So while the hope coming out of this PR is to have some automated scanning to ensure all existing code and any newly introduced code works on all supported PHP versions, until that tool adds full 8.0+ support, we can't guarantee that.

Alternate Designs

None

Possible Drawbacks

We are running more tests now, which will take up more time. Particularly for PHPUnit, we are running tests against PHP 7.0, 7.1, 7.2, 7.3, 7.4, 8.0 and 8.1. Could probably simplify that and only run against 7.0 and 8.1 and still catch most (if not all) issues.

Verification Process

Ensure newly added checks are passing

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

Changelog Entry

Added - More robust PHP testing

Credits

Props @dkotter