BackupCronJob Controller fails for empty DevWorkspace (no PVC)

[rohanKanojia]

Description

The DevWorkspace backup feature works correctly for workspaces with claim-devworkspace PVCs.

However, when a DevWorkspace has an empty template and no PVCs, the backup cron job fails with an error instead of completing successfully or skipping the backup gracefully.

{"level":"error","ts":"2025-12-31T15:52:00Z","logger":"controllers.BackupCronJob","msg":"Failed to get PVC for DevWorkspace","id":"workspacedffe6504447347e7","error":"PersistentVolumeClaim \"claim-devworkspace\" not found","stacktrace":"github.com/devfile/devworkspace-operator/controllers/backupcronjob.(*BackupCronJobReconciler).createBackupJob\n\t/devworkspace-operator/controllers/backupcronjob/backupcronjob_controller.go:367\n..."}

How To Reproduce

1. Enable Backup functionality by applying this DevWorkspaceOperatorConfig (see feat(23570): Add controller for workspace backup #1530 (comment) )
2. Create empty workspace sample from samples/empty.yaml
3. Check DevWorkspaceOperator controller pod logs to see the error

Expected behavior

BackupCronJob should handle empty DevWorkspaces gracefully. Either:

• Skip backup and log an info message, or
• Create a valid empty backup artifact
• Avoid treating missing PVCs as an error when none are expected