git_ui: Fix item heights in git panel (#25833)

- Fixes items slightly overlapping in the git panel
- Fixes commit button in the project diff not opening modal

Release Notes:

- N/A

---------

Co-authored-by: Nate Butler <iamnbutler@gmail.com>
Co-authored-by: Cole Miller <m@cole-miller.net>

crates/git/src/git.rs

@@ -64,7 +64,7 @@ actions!(
         Pull,
         Fetch,
         Commit,
-        ExpandCommitEditor,
+        ShowCommitEditor,
     ]
 );
 action_with_deprecated_aliases!(git, RestoreFile, ["editor::RevertFile"]);