Use isoparse for datetime parsing

tests/python/rest_api/test_labels.py

@@ -13,7 +13,7 @@
 from cvat_sdk import exceptions, models
 from cvat_sdk.api_client.api_client import ApiClient, Endpoint
 from cvat_sdk.core.helpers import get_paginated_collection
-from dateutil.parser import parse as parse_datetime
+from dateutil.parser import isoparse as parse_datetime
 from deepdiff import DeepDiff
 from pytest_cases import fixture, fixture_ref, parametrize