Pull requests tab count doesn't auto-refresh after merging a PR

[ekographs]

After merging a pull request, the count badge on the Pull requests tab still shows the pre-merge number. The count only corrects itself after a manual page reload.

Steps to reproduce:

1. Open a repository with exactly one open pull request — the Pull requests tab shows a count of 1
2. Open that PR and merge it
3. Look at the Pull requests tab count

Expected: The count updates to 0 automatically once the merge completes.

Actual: The count still shows 1. Reloading the page updates it to 0.

Notes: Reproduced with a single open PR, but the same staleness applies to any count the badge does not resync after a merge.

Tested on Microsoft Edge - MAC