git_panel: Add hover state to latest commit button (#46046)

The button for opening the latest commit view didn't have a hover state,
but now it does!

<img width="400" height="548" alt="Screenshot 2026-01-04 at 8  44@2x"
src="https://github.com/user-attachments/assets/6a58fefb-5f3f-4973-b5e8-35c400996e12"
/>

Release Notes:

- N/A
8ef900ce5bDanilo Leal committed on 1/4/2026, 11:58:42 PM· committed by GitHubparent7d0f23d
1 file changedLine totals unavailable