Review and potentially delete AWS S3 buckets that are no longer needed

There are several S3 buckets under the McGovern DANDI AWS account that seem to be test data (and some buckets are empty). As a group, we should decide which ones can be deleted so that we are not paying for this storage.

As a first step, @waxlamp has generated a ~[report](https://waxlamp.github.io/dandi-s3-buckets/DANDI%20-%20investigation%20of%20S3%20bucket%20usage%20-%202024-11-07.html)~ [Google sheet](https://docs.google.com/spreadsheets/d/1wp3-ytcfanvrB4z5DARp8ZJv9KWyd0tjFrBGprybwGI/) that summarizes the buckets.

TODO:
- [ ] meet to discuss buckets and finalize disposition column
- [ ] check which buckets are defined via Terraform