[TASK] Remove unused EditToolbarService

As feedit has been removed from the core,
EditToolbarService is no longer in use.
As it was marked as internal it is removed
without further notice.

Resolves: #90098
Releases: master
Change-Id: I5e8a622c5581e46539afe43a1aed3486c6d5ae11
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62853


Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>