Update a bulk processing job

Cancels a single bulk processing job for an asset. This endpoint currently only supports cancellation.

Request body:

{
  "status": "cancelled"
}

Cancellation is idempotent. Cancelling an already-cancelled job returns the current cancelled job. Completed jobs cannot be cancelled.

When a job is cancelled, pending and in-progress child items are marked cancelled; terminal child items are not modified. The response is the updated job, including cancelled_by.