sdks/python: fix linting issues for enrichment_test.py

Signed-off-by: Mohamed Awnallah <mohamedmohey2352@gmail.com>

Author: mohamedawnallah

sdks/python/apache_beam/examples/snippets/transforms/elementwise/enrichment_test.py

@@ -18,13 +18,13 @@
 # pytype: skip-file
 # pylint: disable=line-too-long
 
-from collections.abc import Callable
-from contextlib import contextmanager
 import os
-from typing import Optional
 import unittest
-from io import StringIO
+from collections.abc import Callable
+from contextlib import contextmanager
 from dataclasses import dataclass
+from io import StringIO
+from typing import Optional
 
 import mock
 import pytest