Increase trailoff limit for modal branch picker. (#2710)

Z-2601

Follow-up to modal branch picker, this is the updated version:

![image](https://github.com/zed-industries/zed/assets/24362066/1017e2d9-7107-4e4c-805e-bae46412079a)
Previously a trail off limit was much smaller:

![image](https://github.com/zed-industries/zed/assets/24362066/efb6c7cf-d90d-4fbc-8c28-84872f215ac5)

Release notes:
- N/A
c12821f6c5Piotr Osiewicz committed on 7/12/2023, 4:07:54 PM· committed by GitHubparents3db1aac6260d97
1 file changedLine totals unavailable