Git Sync Issue on Windows

**Problem**
We added the Git Sync facility to our project and created an .insomnia folder in the root directory of our Git repository. Under Linux, synchronisation works without any problems, but under Windows the branch cannot be changed.

**To Reproduce**
1. Create -> Git Clone
2. Go to Branches -> Checkout other Branch (in our case development)
3. Pull changes

**Expected behavior**
The expected behaviour is that the current changes are loaded from the new branch or the branch is changed.

**Error**

**Stacktrace**
```
MergeNotSupportedError: Merges with conflicts are not supported yet.
at _merge (C:\Users\Finabro\AppData\Local\insomnia\app-2021.4.1\resources\app.asar\node_modules\isomorphic-git\index.cjs:8677:11)
at async _pull (C:\Users\Finabro\AppData\Local\insomnia\app-2021.4.1\resources\app.asar\node_modules\isomorphic-git\index.cjs:8831:5)
at async Object.pull (C:\Users\Finabro\AppData\Local\insomnia\app-2021.4.1\resources\app.asar\node_modules\isomorphic-git\index.cjs:11119:12)
at async GitSyncDropdown._handlePull (file:///C:/Users/Finabro/AppData/Local/insomnia/app-2021.4.1/resources/app.asar/bundle.js:412669:13)
```

**Operating System:**
- OS: Windows 10 21H1 (Build: 19043.1083)
- App Version: 2021.4.1

Start at GitSyncDropdown._handlePull and the isomorphic-git pull path shown in the stack trace, then reproduce the checkout and pull sequence on Windows 10 with the .insomnia repository. Done means switching to the development branch loads its current changes without the unsupported merge-conflict error.

Written by the indexing model from the issue text.