[TASK] Avoid phpunit getMockForAbstractClass()

Deprecated with phpunit 11. Adapt to
fixture classes to test details of abstracts.

Resolves: #103228
Releases: main
Change-Id: Ic0cd4541856beb45775d50d22b95be687888373a
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83160


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