[TASK] Use phpunit attributes in functional tests

phpunit 11 deprecates annotations like `@test` and
`@dataProvider` in favor of their attribute counterparts.

We'll adapt core main & v12 to keep v12 backports
simple. The patch takes care of Tests/Functional and
Tests/FunctionalDeprecated.

Script `Build/Scripts/splitFunctionalTests.php` is
adapted to deal with annotations for CI to continue
splitting functional tests into chunks. This also
fixes detection in two test cases that had unexpected
`@test` annotation combinations which were not properly
detected before.

> composer req --dev rector/rector
> wget https://forge.typo3.org/attachments/download/38273/rector.php
> find typo3/ -name \*Test.php | grep Tests/Functional | xargs bin/rector process
> rm rector.php
> composer rem --dev rector/rector

Minor manual adaption in a few files plus cgl fixes.

Also deny `@test` annotion in annotationChecker.php now
to not introduce new occurences with other patches anymore.
The script will receive another cleanup...