Please consider updating "oauth2client deprecation" to include repo archival

[mgorny]

The doc @ https://github.com/googleapis/google-auth-library-python/blob/main/docs/oauth2client-deprecation.rst indicates:

While oauth2client will not be implementing or accepting any new features, the google-auth team will continue to accept bug reports and fix critical bugs. We will make patch releases as necessary.

However, the https://github.com/googleapis/oauth2client repository is archived. Perhaps the deprecation doc should be updated accordingly indicating that no further patch releases are planned?

A clear message would be helpful for us, as we are trying to convince other projects to stop using oauth2client.

[clundin25]

It looks like this is still being supported by the API client. Let me see if can consider removing that code now.

[clundin25]

Blocking issue: googleapis/google-api-python-client#1490