Merge commit 'be991f1d18006a4820c1e9ca6625bf2bd2bfedac' into glitch-soc/merge-upstream

Conflicts:
- `app/models/form/admin_settings.rb`:
  Upstream added the notion of overriden settings, while we had extra code for
  pseudo-settings (only used to combine flavour and skin in a single select
  field).
  Ported upstream changes.
- `config/i18n-tasks.yml`:
  Upstream added `simple_form.overridden` to `ignore_unused`,
  we had `simple_form.glitch_only`.
  Added `simple_form.glitch_only` as well.

app/controllers/application_controller.rb

@@ -12,6 +12,7 @@ class ApplicationController < ActionController::Base
   include DomainControlHelper
   include ThemingConcern
   include DatabaseHelper
+  include AuthorizedFetchHelper
 
   helper_method :current_account
   helper_method :current_session
@@ -53,10 +54,6 @@ class ApplicationController < ActionController::Base
 
   private
 
-  def authorized_fetch_mode?
-    ENV['AUTHORIZED_FETCH'] == 'true' || Rails.configuration.x.limited_federation_mode
-  end
-
   def public_fetch_mode?
     !authorized_fetch_mode?
   end