perf: remove RoomEvent.UnreadNotifications from ThreadReplyChip

Fired on every room message, causing N×chip re-renders and O(n_events)
scans per message when N threads are visible. ThreadEvent.NewReply/Update
and RoomEvent.Redaction already cover the relevant updates.

Author: Just-Insane

src/app/hooks/timeline/useTimelineEventRenderer.tsx

@@ -120,12 +120,10 @@ function ThreadReplyChip({
     thread.on(ThreadEvent.NewReply as any, onUpdate);
     thread.on(ThreadEvent.Update as any, onUpdate);
     room.on(RoomEvent.Redaction as any, onUpdate);
-    room.on(RoomEvent.UnreadNotifications as any, onUpdate);
     return () => {
       thread.off(ThreadEvent.NewReply as any, onUpdate);
       thread.off(ThreadEvent.Update as any, onUpdate);
       room.off(RoomEvent.Redaction as any, onUpdate);
-      room.off(RoomEvent.UnreadNotifications as any, onUpdate);
     };
   }, [room, thread]);