This PR fixes an issue where the your commit message inside the git
panel commit editor could be behind the `Open Commit Modal` button.

**Before**
<img width="391" height="180" alt="Screenshot 2026-05-03 at 18 11 33"
src="https://github.com/user-attachments/assets/f9c68665-ca82-4fb0-80e1-d501891f5ef5"
/>

**After**
<img width="359" height="179" alt="Screenshot 2026-05-05 at 18 18 58"
src="https://github.com/user-attachments/assets/1ff610c7-5758-4446-9666-67c194b1d3f9"
/>

Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- Fix git commit message editor text could be behind the `Open Commit
Modal` button