[TASK] Drop PhpStorm meta configuration for getAccessibleMock & friends

This is now covered by the annotations using generics in the testing
framework base class, and hence not needed anymore.

(Removing it also helps get consistent behavior from PhpStorm's
static type analysis.)

Resolves: #97736
Releases: main, 11.5, 10.4
Change-Id: Ia7d7e790bb92eaf1c9b7ffa4f9d97b2b0a50dee3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74769


Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Stefan Bürk <stefan@buerk.tech>