Move backend for CDN to S3 or similar

[pypa]

Move backend for CDN to S3 or similar

[chrahunt]

This should be a bit easier now with GitHub Actions, which can take care of the triggering and holding secrets.

An example of uploading to an s3 bucket on push can be found here.

[ewdurbin]

salt states that "build" bootstrap.pypa.io's assets: https://github.com/python/psf-salt/tree/master/salt/pypa/bootstrap

[dstufft]

The main "problem" with that, which isn't really a problem problem, just something to solve is currently the setup pulls from repositories, so we don't need to distribute secrets anywhere (other than VCS secrets, which we need anyways). Switching to a push based model would mean that we need to distribute S3 keys to all of the projects that are currently publishing to bootstrap.pypa.io.

Another option might be to only support Github repositories as a source of truth, and use lambda to listen for push hooks from GitHub, and automatically fetch and upload to S3 in response to them?