[BUGFIX] Resolve type inconsistency in ComparisonInterface

ComparisonInterface's documented types and actual types are
inconsistent. This patch corrects the types to be consistent
with what the actual code does, which allows for the removal
of several PHPStan errors.

Resolves: #97604
Releases: main
Change-Id: Ib58def06b4c702443f4aac63a667cadfac26dc49
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74655


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