v0.0.0-6375-g7102b8489

github_workflows/doc: publish doc continuously

- enable on push
- enable on pull_request (this will skip deploy per: https://docs.github.com/en/pages/getting-started-with-github-pages/configuring-a-publishing-source-for-your-github-pages-site#creating-a-custom-github-actions-workflow-to-publish-your-site)

follow-up to #1463

PiperOrigin-RevId: 696733559