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

https://github.com/python/cpython/blob/f383ca1a6fa1a2a83c8c1a0e56cf997c77fa2893/Objects/stringlib/join.h#L123

homeassistant/components/api/__init__.py

@@ -222,7 +222,7 @@ class APIStatesView(HomeAssistantView):
                 if entity_perm(state.entity_id, "read")
             )
         response = web.Response(
-            body=b"[" + b",".join(states) + b"]",
+            body=b"".join((b"[", b",".join(states), b"]")),
             content_type=CONTENT_TYPE_JSON,
             zlib_executor_size=32768,
         )

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"]"))
+        )
     )