[BUGFIX] Fix PHP warning when checking for resource collection object

Used command(s):

> Build/Scripts/runTests.sh -s phpstanGenerateBaseline

Resolves: #98603
Releases: main, 11.5
Change-Id: I83aa10d188495fae7a7cac9179ec0c7d362eedcf
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76068


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>