[TASK] Simplify FileBackend->remove()

Throw if frozen, then call ->remove() of SimpleFileBackend

Resolves: #93239
Related: #92847
Releases: master
Change-Id: I01fe5d79b9adc48491ece5ed360be4e94c0e53af
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/67359


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>