Per job artifacts
Put artifacts in a per-job folder, because if a job is retried then it will try to upload a file to the same key and fail with the following error:
2020-07-22T16:26:13 requests.exceptions.HTTPError: 403 Client Error: Forbidden for url: https://minio-packet.freedesktop.org/artifacts/daenzer/mesa/180609/gl-panfrost-t860/results.yml