Success Promotion stuck in "Initiating deployment"

**Issue**
After promoting a bundle with only one work item to Production, the pipeline got stuck in "Initiating deployment". All components has been pushed to the Target Org and the PR has been merged. However, the Pipeline keeps shows "Initiating deployment" and no items are returned when running the SOQL to catch stale "In Progress" items:

`SELECT Id, sf_devops__Status__c FROM sf_devops__Work_Item_Promote__c
WHERE sf_devops__Status__r.sf_devops__Status__c = 'In Progress'`

The whole pipeline is stuck and no other items can be promoted to other stages, unless run via the MCP. Back-Sync still running.

Start with the Success Promotion flow and the SOQL query for sf_devops__Work_Item_Promote__c items, then trace the "Initiating deployment" state and Back-Sync status. Compare the completed push and merged PR with the pipeline state; done means the promotion leaves that state and subsequent stage promotions work without the MCP.

Written by the indexing model from the issue text.