Fix notification screen crashing in rare cases where the status no longer exists (#31403)

app/javascript/mastodon/features/notifications_v2/components/notification_mention.tsx

@@ -37,7 +37,11 @@ export const NotificationMention: React.FC<{
   unread: boolean;
 }> = ({ notification, unread }) => {
   const [isDirect, isReply] = useAppSelector((state) => {
-    const status = state.statuses.get(notification.statusId) as Status;
+    const status = state.statuses.get(notification.statusId) as
+      | Status
+      | undefined;
+
+    if (!status) return [false, false] as const;
 
     return [
       status.get('visibility') === 'direct',

app/javascript/mastodon/features/notifications_v2/components/notification_with_status.tsx

@@ -23,7 +23,7 @@ export const NotificationWithStatus: React.FC<{
   icon: IconProp;
   iconId: string;
   accountIds: string[];
-  statusId: string;
+  statusId: string | undefined;
   count: number;
   labelRenderer: LabelRenderer;
   unread: boolean;
@@ -76,6 +76,8 @@ export const NotificationWithStatus: React.FC<{
     [dispatch, statusId],
   );
 
+  if (!statusId) return null;
+
   return (
     <HotKeys handlers={handlers}>
       <div