[BUGFIX] Add correct id to "Not assigned to any task group"

The group of "Not assigned to any task group" can not be
collapsed anymore.

This has been fixed by adding the correct id, so the
element to collapse is found and collapsed again.

Resolves: #100308
Releases: main
Change-Id: I08c705cea67d03c02667cc6753752b385339733f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78264


Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>