Make doc previews use its own S3 bucket (#64594)
Summary:
We had been using the gha-artifacts bucket (which previously only stored workflow artifacts) to keep the docs around. This makes it hard to see how our storage for artifacts vs docs is trending.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64594
Reviewed By: seemethere
Differential Revision: D30794328
Pulled By: driazati
fbshipit-source-id: 6b2721a3d76e8a273bde055783d56551f8409edd
