Regression in SIMPLETEST environment skipping

Doesn't look like this was fully working anymore and still had the old php class names so a bunch of updates.

1) Moved this out of a dedicated listener and integrated it into the existing DrupalListener. This fixes the legacy PHPunit classes but also avoids changes to phpunit.xml files and avoids adding any deprecated code since listeners are technically deprecated now in PHPunit 8/9 to be removed in 10.
2) Fixed the skipped logic in Functional tests that wasn't correctly triggering the Simpletest warning. This got lost I think accidentally in an earlier patch.
3) Ported this logic to TestSiteApplicationTest as well.

Alternatively this might be converted to PHPunit events? 10 requires PHPunit 9 so that would seem to be an option but I don't see that anywhere in core and I don't have any experience so I didn't move that far.

reroll. Conflicted with 🐛 InfoParser returns an empty array if passed a non-existing file Fixed

This needs to be re-built now that symfony's listener is out of the mix and we're on phpunit 10. Its likely less complicated but I need to look at it.

Just a note that PHPUnit 12 (due Feb 2025) will provide a #[RequiresEnvironmentVariable] attribute that

can be used to skip the execution of a test when the specified environment variable is not set

https://github.com/sebastianbergmann/phpunit/issues/6065