Very long staging for multiple files while rebasing

**Describe the bug**
Very long staging for multiple files(~490 files) almost 10 min in Interactive Rebasing, while the first "clean" staging was quickly.

**To Reproduce**
Steps to reproduce the behavior:

1. Init git
2. Download Mozilla PDFJS for testing purposes or select your own https://github.com/mozilla/pdf.js/releases/download/v3.6.172/pdfjs-3.6.172-dist.zip
3. Run lazygit. Stage added files(~490 files) (as usual the speed is fast) and commit it.
4. Go to `Commits` tab, select added commit and press e to edit it
6. Press Enter to see `Diff files`
7. Stage entire folder. And it will totally freeze for 10 minutes. And after staging, it will work with a freeze until restarting lazygit.

**Expected behavior**
it should work as fast as the first "clean" staging (as noted on the step 2)

**Screenshots**

https://github.com/jesseduffield/lazygit/assets/31704887/3501fd3f-3cc5-4ce3-ac88-2d686fc04175

**Version info:**
`lazygit --version`
```
commit=v0.38.2, build date=2023-05-03T15:21:01Z, build source=binaryRelease, version=0.38.2, os=linux, arch=amd64, git version=2.40.1
```

`git version 2.40.1`

**Additional context**
Add any other context about the problem here.

**Note:** please try updating to the latest version or [manually building](https://github.com/jesseduffield/lazygit/#manual) the latest `master` to see if the issue still occurs.