Use bytes join fast path for large states payload (#110694)

b"".join has a fast path for when there are more than two bytes-strings
to combine

f383ca1a6f/Objects/stringlib/join.h (L123)

homeassistant/components/websocket_api/commands.py

@@ -356,7 +356,9 @@ def _send_handle_get_states_response(
 ) -> None:
     """Send handle get states response."""
     connection.send_message(
-        construct_result_message(msg_id, b"[" + b",".join(serialized_states) + b"]")
+        construct_result_message(
+            msg_id, b"".join((b"[", b",".join(serialized_states), b"]"))
+        )
     )