TASK: Flow 7 compatibility

[simstern]

Tiny change to comply with the current phpunit version used in Flow 7.
Please tag a new version when merging :-)

[riea]

Without the changes in this PR to the setUp function declaration, i get an error complaining about the compatibility of the method declaration on Flow 8.2 (on PHP 8.1) as well:

Exception #1355480641 in line 392 of /var/www/html/Packages/Framework/Neos.Flow/Classes/Core/Booting/Scripts.php: PHP Fatal error: Declaration of Flowpack\JobQueue\Redis\Tests\Functional\Queue\RedisAuthenticationTest::setUp() must be compatible with Neos\Flow\Tests\FunctionalTestCase::setUp(): void in /var/www/html/Packages/Application/Flowpack.JobQueue.Redis/Tests/Functional/Queue/RedisAuthenticationTest.php on line 43

[bwaidelich]

Thanks!