[TASK] Make type annotations for ObjectStorage::toArray more specific

This helps static analysis of projects using this class.

Resolves: #100778
Releases: main, 11.5
Change-Id: I41cbf38477fb6743e5039dd9905ed38be81e96fc
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78915


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>