[UI] Pull Requests table on Repository page is not sortable

[edwin-rivera-dev]

Description

On a repository's Pull Requests tab, the table column headers (PR #, Title, Author, Commits, +/-, Score, Status, Merged) look like normal column headers but are not clickable. The list is always sorted by Score descending, and there's no way to reorder it.

Other tables on the site — Repositories, Languages, and the leaderboards — already support clicking a column to sort, with a small arrow indicator showing the active column and direction. The Pull Requests table feels like the odd one out.

Steps to Reproduce

1. Open any repository detail page, for example:
   https://gittensor.io/miners/repository?name=entrius/gittensor-ui
2. Click the Pull Requests tab
3. Try clicking any column header (PR #, Title, Author, Commits, +/-, Score, Status, Merged)
4. Nothing happens — the rows stay sorted by Score

Expected

• Clicking a column header sorts the table by that column
• Clicking the same header a second time flips between ascending and descending
• A small arrow appears on the active column showing the direction
• Default sort on first load stays as it is today (Score, descending) so nothing regresses for existing users

Actual

• The column headers do nothing when clicked
• Only the default Score sort is available

Why it matters

Users currently have no way to find the oldest / newest PR, filter by author, or scan by PR number. The data is there, but only one view of it is available.

Screenshot

Environment

• Browser: any
• URL: https://gittensor.io/miners/repository?name=<any repo> → Pull Requests tab