git: Fix spurious file creation when staging (#53621)

Related to https://github.com/zed-industries/zed/pull/53484. 

This PR fixes a `--` file being created when staging a hunk.

Release Notes:

- N/A
e6196e2216Neel committed on 4/10/2026, 1:16:43 PM· committed by GitHubparent3c4e235
1 file changedLine totals unavailable