GitHub PR view highlights all repos with Copilot notification

Testing #264266

Although coding agent created a PR for a single repo, all repos in the workspace get a notification:

<img width="479" height="648" alt="Image" src="https://github.com/user-attachments/assets/724f7de4-5f44-484f-a6f1-062ec4b2e16d" />