[BUGFIX] Prevent array access warning on deleted database record

If a sys_file record is directly deleted from database, some undefined
array index warnings are triggered if the file is assigned to another
database record.

Releases: main, 11.5
Resolves: #97987
Change-Id: I2ce115024e637cffacc512528e79b1bb4059f173
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75254


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