CI red: MinIO was deleted from Docker Hub, breaking dandi-cli's compose stack

The scheduled `Test` run has been failing since 2026-09-13 ([run 284](https://github.com/dandi/backups2datalad/actions/runs/34742777134)); [run 283](https://github.com/dandi/backups2datalad/actions/runs/34016329427) on 2026-09-06 was the last green one. Every Python leg shows the same shape — `38 passed, 1 skipped, 17 errors` — and all 17 errors are:

```
subprocess.CalledProcessError: Command '['docker', 'compose', 'pull']' returned non-zero exit status 1.
```

**Nothing to fix in this repo.** There is no compose file or `image:` here — `test/conftest.py` imports `dandi.tests.fixtures`, and `local_dandi_api` transitively runs `dandi/tests/data/dandiarchive-docker/docker-compose.yml` out of the installed `dandi` package. That file pinned `minio/minio:latest`, and MinIO deleted the `minio/minio` and `minio/mc` Docker Hub repositories in September 2026:

```
hub.docker.com/v2/repositories/minio/minio/ -> 404
hub.docker.com/v2/repositories/minio/mc/ -> 404
```

The fix is dandi/dandi-cli#1921, which points the stack at Quay (the archived community images are still served there) and pins the tag.

**This repo needs a dandi-cli _release_, not just that merge.** `pyproject.toml` declares `dandi >= 0.75.1` and tox installs from PyPI, so the compose file arrives inside the `dandi` wheel (it ships via `graft dandi`). CI goes green on its own once a dandi-cli release containing #1921 is on PyPI — the floor is a lower bound, so no version bump is needed here.

Worth closing this once that release lands and a run comes back green.

Start with test/conftest.py and pyproject.toml, then inspect scheduled Test run 284 and dandi-cli#1921. Confirm that a dandi-cli release containing the compose-image fix is available on PyPI, rerun or await CI, and close this issue once the scheduled run is green.

Written by the indexing model from the issue text.