Instead of failing the ingestion, fallback to use the artifact's mtime (if
Note that most origins have their upload 'time' provided. In the error
referenced , the origins sampled there show that they have their 'mtime'
referenced instead of the 'time'.
Also, if no upload time is provided at all, skip the artifacts altogether. This
allows ingestion of further artifacts for the same origin instead of failing
completely the origin ingestion.