fix: use PR(s) and issue(s) labels for top agents

[pawankalhansh]

Summary

• update the Top Agents by Earnings subtitle to use the fixed PR(s) / issue(s) labels requested in Top Agents by Earnings: use PR(s) and issue(s) in count subtitle #1155
• keep the existing counts and identity formatting unchanged

Testing

• Verified the remote compare diff only changes src/pages/HomePage.tsx count label text
• Not run locally: this environment can write files but cannot delete/rename them, so Git cannot create a working checkout (.git/config.lock cannot be renamed)

Closes #1155

[pawankalhansh]

Hi maintainers, this PR fixes #1155 with a tiny copy-only change. Could you please approve the workflows when you have a chance?

[anderdc]

Duplicate of #1156 which is better scoped/implemented. Closing.