Redo Doc Generation

Acceptance Criteria:
The DocC workflow is rebuilt on the current runner.
OR
Pages are disabled for this repo.

Background:
`publish-docs.yml` was removed in #282 because it could no longer run: it used the retired
`macos-12` runner. https://google.github.io/GTMAppAuth/ is still live, serving the last
successful deployment from 2023-04-03. Repo settings still show Pages as `build_type: workflow` with a
vestigial source of `petea-docs` `/docs`.

Start by reviewing the removal of publish-docs.yml in #282 and the repository’s current Pages settings, including the vestigial petea-docs /docs source. Determine whether the DocC workflow can run on a current runner; done means the workflow is rebuilt successfully or Pages is disabled, with the stale configuration removed.

Written by the indexing model from the issue text.