remove unused imports

thanks flake8!

tests/test_pipeline_files.py

@@ -5,7 +5,7 @@ from datetime import datetime
 from io import BytesIO
 from shutil import rmtree
 from tempfile import mkdtemp
-from unittest import mock, skipIf
+from unittest import mock
 from urllib.parse import urlparse
 import dataclasses
 

tests/test_pipeline_images.py

@@ -3,7 +3,6 @@ import io
 import random
 from shutil import rmtree
 from tempfile import mkdtemp
-from unittest import skipIf
 import dataclasses
 
 import attr