SymbolicLink causes staging problems on Windows.

### Godot version

4.5.stable.steam

### Godot Git Plugin version

3.2.1

### System information

Windows 10

### Issue description

.
├── addons
│  ├── test_folder --> // New contents
│   ├── godot-git-plugin // 3.2.1 latest plugin
│   └── godotsteam
├── assets
│   └── UI -> E:\UI // A symbolicLink
...
├──.gitignore

Among which, assets contains a windows SymbolicLink `UI to E:\UI`, `.gitignore` contains `assets\` item.
`git status` output doesn't contain `assets` folder.
But in Godot, the plugin section shows `assets/UI` folder which shouldn't. And I cannot stage any second level folder and contents like `addons/test_folder/**`. The log shows:
```
Error -3: requested file is a directory in godot-git-plugin\src\git_plugin.cpp:GitPlugin::_stage_file#L158
```
However, all manual git operation can be done normally in command line. I can also stage project root folder contents like `.gitignore` normally.

### Steps to reproduce

Create a blank project in windows, with latest godot-git-plugin installed.
Add symboliclink using `New-Item [LinkName] -Itemtype SymbolicLink -Target [TargetAbsolutionPath]`.
Try staging any second level contents in godot.