* Optimize map { ... }.compact

using Enumerable#filter_map, supported since Ruby 2.7

* Add poyfill for Enumerable#filter_map

Fix #7265

* 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