[TASK] Enable phpstan PHPStan\Rules\Classes\ImpossibleInstanceOfRule

Releases: master
Resolves: #90910
Change-Id: If03889ee330e96c5ca82b31ae0604fb1d1d0afc8
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64031


Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>