[BUGFIX] Prevent invalid array access warnings in DataHandler

Resolves: #97280
Releases: main, 11.5
Change-Id: Id6b2b5bf9a200d7c0ccc6c23273bb5086d6ee50a
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74154


Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Bartsch <bo@cedev.de>