[Jenkins-infra] Migrating hosted Artifactory database to include SHA-256

[Daniel Beck]

Hi JFrogs,

As always, thanks for hosting the Jenkins project's Artifactory!

I would like repo.jenkins-ci.org to be migrated to a database that includes SHA-256 checksums for all past artifacts. I tried `/api/checksum/sha256` first, but that doesn't actually result in checksums being added to `/api/storage/<repo>/?list&deep=1`, so doesn't fit our intended purpose.

Since this Artifactory is hosted by you, I cannot initiate this process myself. I would like to schedule a migration. Is this possible?

Thanks!
Daniel

(Jenkins project reference: INFRA-1696)