[TASK] Make all internal class in EXT:core strict

Resolves: #101378
Releases: main
Change-Id: I9b8006f65b0805185dc189dce8e19024497326d2
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80009


Tested-by: Stefan B�rk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan B�rk <stefan@buerk.tech>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>