[TASK] Use strict type checking in TreelistCacheUpdateHooks

Resolves: #78836
Releases: master
Change-Id: Ib76c95164e228ce3a8afa448cf4a9c1ba6ddec29
Reviewed-on: https://review.typo3.org/50772


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Manuel Glauser <mail@manuelglauser.ch>
Tested-by: Manuel Glauser <mail@manuelglauser.ch>
Reviewed-by: Jan Helke <typo3@helke.de>
Tested-by: Jan Helke <typo3@helke.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>