[TASK] Cleanup types in ArrayAccessClass

Not marking this as breaking since it's a test fixture only.

Resolves: #98034
Releases: main
Change-Id: Id2dd650c617f5be807d3615751466102d274cea3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75309


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>