[BUGFIX] Fix notice in DataHandler if deleting a record

Check if a field exists before accessing it.

Resolves: #101852
Releases: main, 12.4, 11.5
Change-Id: I95d227d920975b1e348c95a1069a9ddddcddc900
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80850


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Stefan Bürk <stefan@buerk.tech>