[TASK] Update testing framework to 5.0.12

    composer require typo3/testing-framework:"~5.0.12"

Resolves: #89073
Releases: master
Change-Id: If6384d11c0201cea760b384a8b7d7b361874e815
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61617


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>