git_panel: Allow to switch between changes and history tab with keyboard (#56743)

Follow-up to https://github.com/zed-industries/zed/pull/56500. Was
missing this ability very much :)

Release Notes:

- Git Panel: Added the ability to switch between the changes and history
tabs with the keyboard.
c937fc6e33Danilo Leal committed on 5/14/2026, 1:11:14 PM· committed by GitHubparent80b11f4
4 files changedLine totals unavailable