Add Ruby 3.0 support (#16046)

* Fix issues with POSIX::Spawn, Terrapin and Ruby 3.0

Also improve the Terrapin monkey-patch for the stderr/stdout issue.

* Fix keyword argument handling throughout the codebase

* Monkey-patch Paperclip to fix keyword arguments handling in validators

* Change validation_extensions to please CodeClimate

* Bump microformats from 4.2.1 to 4.3.1

* Allow Ruby 3.0

* Add Ruby 3.0 test target to CircleCI

* Add test for admin dashboard warnings

* Fix admin dashboard warnings on Ruby 3.0

app/controllers/api/v1/follow_requests_controller.rb

@@ -29,7 +29,7 @@ class Api::V1::FollowRequestsController < Api::BaseController
   end
 
   def relationships(**options)
-    AccountRelationshipsPresenter.new([params[:id]], current_user.account_id, options)
+    AccountRelationshipsPresenter.new([params[:id]], current_user.account_id, **options)
   end
 
   def load_accounts