chore: oneShotSync before staleCallChecker

fix: while singleShotStaleCallChecker code seems to be correct we are seeings some random disconnects in group calls, this makes sure we have all the to-device messages we are supposed to have before checking for stale calls

lib/src/voip/voip_room_extension.dart

@@ -86,6 +86,8 @@ extension GroupCallUtils on Room {
 
   Future<void> singleShotStaleCallCheckerOnRoom() async {
     Logs().d('checking for stale group calls in room $id');
+    // make sure we have all the to-device messages we are supposed to have
+    await client.oneShotSync();
     final copyGroupCallIds =
         states.tryGetMap<String, Event>(EventTypes.GroupCallPrefix);
     if (copyGroupCallIds == null) return;