Release swh.model v4.1.0 - Drop pre-3.6 blake2 compatibility, which hasn't been in use since we've mandated python3.7 anyway.
staging instance, all data can be removed at all time
Release swh.model v4.1.0 - Drop pre-3.6 blake2 compatibility, which hasn't been in use since we've mandated python3.7 anyway.