Revert "workspacesView: Work around spurious allocation changes"

Revert "workspacesView: Work around spurious allocation changes"

We now found the underlying bug: The ControlsManager (which causes the
bad call to `_updateWorkspacesFullGeometry()`) is getting (re-)allocated
while we add the view to the overviewGroup actor because the
overviewGroup is already visible and the view is immediately getting
mapped by `clutter_actor_add_child_internal()`. That causes a
resource-scale calculation and that indirectly causes a call to
`_clutter_stage_maybe_relayout()` (explained more detailed in the last
commit).

So now that we got rid of the immediate relayout happening when mapping
the view, we can revert this fix.

This reverts commit 6cc19ee6f05102baef39b8a1bec73eff06699879.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1315