Make timeout an optional param in KeyWatcher.updates

nats/js/kv.py

@@ -318,7 +318,7 @@ async def stop(self):
             """
             await self._sub.unsubscribe()
 
-        async def updates(self, timeout=5.0):
+        async def updates(self, timeout: Optional[float] = 5.0):
             """
             updates fetches the next update from a watcher.
             """