Fix a few lint issues

Author: adamtheturtle

tests/mock_vws/test_unexpected_json.py

@@ -10,12 +10,8 @@
 from requests import codes
 from requests.structures import CaseInsensitiveDict
 
-from mock_vws._constants import ResultCodes
 from tests.mock_vws.utils import Endpoint
-from tests.mock_vws.utils.assertions import (
-    assert_vwq_failure,
-    assert_vws_failure,
-)
+from tests.mock_vws.utils.assertions import assert_vwq_failure
 from tests.mock_vws.utils.authorization import (
     authorization_header,
     rfc_1123_date,