[TASK] Raise typo3/testing-framework:^6.11.0

Brings preparations for PHP 8.1 and some further
minor goodies.

composer req --dev typo3/testing-framework:^6.11.0

Change-Id: I4e8d4b31a66c7775801d7abb6243e98c00d2833b
Resolves: #95185
Releases: master, 10.4
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71018


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>