chore(deps): update dependency pytest to v5.4.3 [(#4279)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/4279)
chore(deps): update dependency pytest to v5.4.3 [(#4279)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/4279)

* chore(deps): update dependency pytest to v5.4.3

* specify pytest for python 2 in appengine

Co-authored-by: Leah Cole <d7cd7ba333275e71ca359a2e20dc85dbf2c605f7@google.com>
GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples