Deploy the latest version of swh.model and swh.storage to staging.
- [x] make sure all new packages are available (swh.model, swh.storage, swh.deposit)
- [ ] run the first half of the database migration, adding new fields
- [ ] stop all workers
- [ ] upgrade and restart gunicorn-swh-storage instances (storage1, webapp)
- [ ] upgrade and restart all workers
- [ ] check that new revisions and releases are getting the new offset fields populated
- [ ] run the data migration for the new fields on old objects
- [ ] add database constraints for all objects once the migration has run