message: Improve performance of widget startup slightly
  See
diff: @@ -301,7 +301,8 @@ export class StopGapWidget extends EventEmitter {
  // requests timeline capabilities in other rooms down the road. It's just easier to manage here.
  for (const room of MatrixClientPeg.get().getRooms()) {
  // Timelines are most recent last
  - const roomEvent = arrayFastClone(room.getLiveTimeline()?.getEvents() || []).reverse()[0];
  + const events = room.getLiveTimeline()?.getEvents() || [];
  + const roomEvent = events[events.length - 1];
  if (!roomEvent) continue; // force later code to think the room is fresh
  this.readUpToMap[room.roomId] = roomEvent.getId();
  }
  