Don't exclude 'Gitlab/MarkUsedFeatureFlags' cop
What does this MR do?
It seems using --except Gitlab/MarkUsedFeatureFlags
somehow disable RuboCop's cache, so let's not use it.
We do run the Gitlab/MarkUsedFeatureFlags
cop alone with the cache disabled in another task anyway.
Related to #334246 (closed).
Edited by Rémy Coutable