Every Backup which the user created before the upgrade are gone - NOT listed under backup inventory
*Steps to Reproduce:*
#1 Take Backup of the service
#2 Upgrade PMM-SERVER from 2.19.0 -> 2.20.0
#3 navigate back to /graph/backup/inventory
- backup inventory is empty.
- UPDATE :
- Artifacts are actually kept in storage.
- backup_locations & artifacts tables have records even after update
& *Expected Result:*
Backups should be still visible at backup inventory after upgrade