chore: Change primary actor to Conversation for all the notification types. (#8435)

db/migrate/20231201014644_remove_notifications_with_message_primary_actor.rb

@@ -0,0 +1,5 @@
+class RemoveNotificationsWithMessagePrimaryActor < ActiveRecord::Migration[7.0]
+  def change
+    Migration::RemoveMessageNotifications.perform_later
+  end
+end