The source project of this merge request has been removed.
Remove python-mock, Use PEP 517 workflow, Use SPDX license
- Remove python-mock
- I did not use https://github.com/googleapis/google-auth-library-python/pull/1361 as does not apply cleanly to system_tests/secrets.tar.enc
- Change to a PEP 517 based workflow
- Change to SPDX license identifier