Lazygit stuck in “Rebasing” state when .git/rebase-merge is partially written

### Describe the bug
Lazygit enters a permanent rebase state and becomes non-functional, even though Git itself reports that no rebase is in progress.

Attempting to abort, skip, or continue the rebase from lazygit results in the following error: `Warning: Could not read '.git/rebase-merge/head-name': No such file or directory

`Restarting lazygit only opens it up in the same state.

Deleting the following manually immediately resolved the issue:
```
rm -r .git/rebase-merge
rm .git/ORIG_HEAD
```

### To Reproduce
I have not been able to reliably reproduce this issue.

It happened while interacting with the latest commit (using `e` or `s` in lazygit). Subsequent attempts using the same steps did not trigger the issue, and the rebase could be aborted normally.

### Expected behavior
Consistent and graceful error handling or ability to abort rebase.

### Screenshots

### Version info:
```
$ lazygit --version
commit=, build date=, build source=nix, version=0.57.0, os=linux, arch=amd64, git version=2.52.0

$ git --version
git version 2.52.0
```

### Additional context
At the time of the issue, the `.git/rebase-merge/` directory existed but contained only a single file. The expected `head-name` file was missing.

Initially I suspected this might have been triggered by a permission error while editing a file during the rebase. However, after further testing (including intentionally creating directories without write permissions), I was unable to reproduce the issue, so this may not be directly related to permissions.

I am running on NixOS, and this occurred shortly after checking for updates.