Add admin notifications for new Mastodon versions (#26582)

app/presenters/initial_state_presenter.rb

@@ -3,9 +3,13 @@
 class InitialStatePresenter < ActiveModelSerializers::Model
   attributes :settings, :push_subscription, :token,
              :current_account, :admin, :owner, :text, :visibility,
-             :disabled_account, :moved_to_account
+             :disabled_account, :moved_to_account, :critical_updates_pending
 
   def role
     current_account&.user_role
   end
+
+  def critical_updates_pending
+    role&.can?(:view_devops) && SoftwareUpdate.urgent_pending?
+  end
 end