Kopia uploader leaks incomplete snapshots

[Lyndon-Li]

During backup, Kopia uploader periodically (every 45 min by default) creates incomplete snapshots, these snapshot won't be recorded by Velero backup and should be deleted automatically after the complete snapshot finishes or after some time (4 hours by default) or after some accumulations (3 by default).
However, Velero failed to call the functionality of auto deletion, as a result, some snapshots will be leaked.