[TASK] Remove obsolete field from EM domain_model_extension

Field / column 'repository' is obsolete since #92457,
but couldn't be removed at this point in time. It's
possible now.

Resolves: #104102
Related: #92457
Releases: main
Change-Id: I5ebcc65f5f9520b065ad3bddba728566b1264325
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84704


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