Mirroring a PyPI version passed each file's sha256 as the integrity
GetOrFetchArtifactFromURLWithIntegrity records with the version. Wheels of
one version share the name and version they are cached under, so the last
file's checksum replaced the others', and serving the other wheels from
the cache failed the integrity check.
The mirror now passes the sha256 as a digest, which is checked against
that file's content hash alone.
proxy mirror and mirror jobs failed for pypi with "unsupported
ecosystem", since the resolver they use has no registry for it. A PyPI
version has several files, so the mirror now lists them from
upstream.pypi's JSON API, through the same client as version listing,
and fetches each one, verified against its sha256. The file_name
qualifier limits it to one file.
Files are cached under the name and version the download handler reads
from the filename, which can differ from the PURL (zope.interface's
wheels are zope_interface), so pip is served them from the cache.
