[BUGFIX] Resolve type issues in SemaphoreLockStrategy

ftok() doesn't return false, but -1 on error.

The $resource property may be null to indicate no lock
is active, so allow that.

Resolves: #97644
Releases: main, 11.5
Change-Id: I88eb20b2399c119390c7e6c34c985a87706db4d3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74696


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