Also:

- Fix locks not being removed when jobs go to the dead job queue
- Add UI for managing locks to the Sidekiq dashboard
- Remove unused Sidekiq workers

Fix #13349

* Ensure SynchronizeFeaturedCollectionWorker is unique and clean up

Fix #7041

* Fix code style issue

* Federate pinned statuses over ActivityPub

* Display pinned toots in web UI

Fix #6117

* Fix migration

* Fix tests

* Update outbox_serializer.rb

* Update remove_serializer.rb

* Update add_serializer.rb

* Update fetch_featured_collection_service.rb