chore(deps): update dependency google-auth to v1.21.1 [(#4634)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/4634)
chore(deps): update dependency google-auth to v1.21.1 [(#4634)](https://github.com/GoogleCloudPlatform/python-docs-samples/issues/4634)


googleapis/python-language,googleapis/python-language