fix(github-pull-requests): introduce max 1000 item paging

[dzemanov]

Description

GitHub Search API has limit of max 1000 results. This causes 422 errors when the search returns more than 1000 items.

{
  "message": "Only the first 1000 search results are available",
  "documentation_url": "https://docs.github.com/v3/search/",
  "status": "422"
}

Modifications

Restrict pagination to a maximum of 1000 items. Show users when additional results are available, suggesting in a tooltip that they can refine their query to retrieve more specific results.

Before:

After:

https://github.com/user-attachments/assets/d9898013-9cd7-4fec-94bf-47955748c1c4

Fixes

1596

:heavy_check_mark: Checklist

• [ ] Added tests for new functionality and regression tests for bug fixes
• [X] Added changeset (run yarn changeset in the root)
• [X] Screenshots of before and after attached (for UI changes)
• [ ] Added or updated documentation (if applicable)