www/typo3-11: Re-enable with PHP 8.1

The documentation mentions only PHP 8.0 as supported. However according
to the 11.5.3 release notes PHP 8.1 is supported. Subsequent releases
added more PHP 8.0 and 8.1 compatibility fixes.

(cherry picked from commit 0ecdbd4617e30459ecc5e395e991c3dddb066c24)