FIX: Clear notification of skipped narrative bot PM (#10792)

Resets a new user's PM count in their badge after skipping user tips.

plugins/discourse-narrative-bot/spec/user_spec.rb

@@ -123,6 +123,8 @@ describe User do
           user.user_option.save!
         }.to change { Topic.count }.by(-1)
           .and change { UserHistory.count }.by(0)
+          .and change { user.unread_high_priority_notifications }.by(-1)
+          .and change { user.notifications.count }.by(-1)
       end
     end