Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Upstream updated copyright year, we don't mention it so kept our version.
- `app/controllers/admin/dashboard_controller.rb`:
  Not really a conflict, upstream change (removing the spam checker) too close
  to glitch-soc changes. Ported upstream changes.
- `app/models/form/admin_settings.rb`:
  Same.
- `app/services/remove_status_service.rb`:
  Same.
- `app/views/admin/settings/edit.html.haml`:
  Same.
- `config/settings.yml`:
  Same.
- `config/environments/production.rb`:
  Not a real conflict, upstream added a default HTTP header, but we have
  extra headers in glitch-soc.
  Added the header.

app/services/process_mentions_service.rb

@@ -43,7 +43,6 @@ class ProcessMentionsService < BaseService
     end
 
     status.save!
-    check_for_spam(status)
 
     mentions.each { |mention| create_notification(mention) }
   end
@@ -72,8 +71,4 @@ class ProcessMentionsService < BaseService
   def resolve_account_service
     ResolveAccountService.new
   end
-
-  def check_for_spam(status)
-    SpamCheck.perform(status)
-  end
 end