ci(actions): fix contributor list action failing (#10651)

**Related Issue:** #8010 

## Summary
Spent way too long hunting down a solution to a generic "Error: Not
found" error message and found nothing, but it turned out to be just a
case sensitive default path 🤦 so this should fix it. 🤞

(Tested in my test repo)

![image](https://github.com/user-attachments/assets/bee9c595-cb97-4a84-89af-2e828d969516)

.github/workflows/contributors.yml

@@ -14,3 +14,5 @@ jobs:
         uses: akhilmhdh/[email protected]
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          readme_path: readme.md