fix: fix no specification assertion

Signed-off-by: wayner0628 <a901639@gmail.com>

tests/flytekit/unit/remote/test_remote.py

@@ -598,7 +598,7 @@ def test_execution_name(mock_client, mock_uuid):
         [
             mock.call(ANY, ANY, "execution-test", ANY, ANY),
             mock.call(ANY, ANY, "execution-test-" + test_uuid.hex[:19], ANY, ANY),
-            mock.call(ANY, ANY, "", ANY, ANY),
+            mock.call(ANY, ANY, None, ANY, ANY),
         ]
     )
     with pytest.raises(