Figure out a strategy for release.json

[ebezzi]

release.json is the file that the census library uses to determine the location of the artifacts. This is currently hosted on the public bucket and needs to change. We have a few options:

1. Keep it on the existing bucket (in single-cell-prod). The bucket will need to become private and a Cloudfront rule needs to be created so that the file can be publicly accessible.
   a. This has the advantage that existing clients will not break
   b. Since the builder needs to write to this file, an IAM permission could be necessary if the builder will run on the new account
2. Move the release.json file to the new S3 bucket
   a. This will break existing clients
   b. This might pose additional security concerns, as this file is effectively vulnerable to potential injections
   c. Easiest solution since the builder will write this file after the copy is done to the same bucket
3. Move the release.json file to a different location (API, GitHub, ...)
   a. Will still break existing clients
   b. Likely more complex than necessary.

[atolopko-czi]

If we care about existing api clients (but I don't think we should), we could do 1 and update the s3 urls to the new bucket, but otherwise consider it end-of-life, no further updates. New api clients will find a new release.json in the new bucket.

[pablo-gar]

As per our conversation we should not consider existing client as the API has been flagged unstable, we will make sure to communicate the change to users once we implement it.