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

Conflicts:
- `spec/models/status_spec.rb`:
  Upstream added tests too close to glitch-soc-specific tests.
  Kept both tests.

app/controllers/auth/registrations_controller.rb

@@ -82,13 +82,17 @@ class Auth::RegistrationsController < Devise::RegistrationsController
   end
 
   def check_enabled_registrations
-    redirect_to root_path if single_user_mode? || !allowed_registrations?
+    redirect_to root_path if single_user_mode? || omniauth_only? || !allowed_registrations?
   end
 
   def allowed_registrations?
     Setting.registrations_mode != 'none' || @invite&.valid_for_use?
   end
 
+  def omniauth_only?
+    ENV['OMNIAUTH_ONLY'] == 'true'
+  end
+
   def invite_code
     if params[:user]
       params[:user][:invite_code]