fix(api-core): fix lint and formatting in rest helpers and tests

Author: hebaalazzeh

packages/google-api-core/google/api_core/rest_helpers.py

@@ -16,7 +16,7 @@
 
 import functools
 import operator
-from typing import Any, Dict, List, Optional, Set, Tuple
+from typing import Any, Dict, List, Optional, Tuple
 
 from google.api_core import path_template
 from google.protobuf import json_format

packages/google-api-core/tests/unit/test_rest_helpers.py

@@ -276,5 +276,3 @@ def test_transcode_request_proto_plus_wrapper():
 
     transcoded, _, _ = transcode_request(http_options, mock_proto_plus)
     assert transcoded["uri"] == "/v1/test/proto-plus-field"
-
-