[BUGFIX] Correct ext:beuser BackendUserRepository inheritance

ext:beuser BackendUserRepository extends ext:extbase
BackendUserGroupRepository, which is of course bogus.
It triggers an unneeded call of extbase
BackendUserGroupRepository->initializeObject(), which
explicitely sets respectStoragePage(false) on query
settings. This is redundant since [ctrl][rootLevel] = 1
of the be_user table TCA triggers the same call via
the DataMapper.

Change-Id: Id809f83fae549e859a426a615c0865d84a5c7250
Resolves: #94229
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69317


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>