[!!!][TASK] Remove deprecated restriction classes

Removed classes:
* BackendWorkspaceRestriction
* FrontendWorkspaceRestriction

Resolves: #101000
Related: #100963
Related: #98996
Releases: main
Change-Id: I70e20ec8d90e982fdc0a9b640e1a9df937189518
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79262


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>