[BUGFIX] Prevent undefined array key warning in QueryGenerator

Resolves: #95943
Releases: master
Change-Id: Ibf5c2c9fe776ab3111c172085335541970a41de7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72139


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>