swh.objstorage: Migrate to latest swh.model.hashutil.MultiHash
Remove redundant calls in tests
requirements: Bump to latest dependency
Migrated from D581 (view on Phabricator)
Staging instance, all changes can be removed at any time
Remove redundant calls in tests
requirements: Bump to latest dependency
Migrated from D581 (view on Phabricator)