#3403 smf: Rollback of single step upgrade with cluster reboot is not implemented

[Thang Duc Nguyen]

Single step upgrade procedures that involve a cluster reboot (SmfStepTypeClusterReboot and SmfStepTypeClusterRebootAct) had no rollback implementation — the rollback() method simply logged an error and returned false. Additionally, the campaign was unconditionally marked as non-rollbackable after a cluster reboot during execute, preventing any rollback attempt.