Failed to run "git fetch"

**Bug description**

As mentioned in https://github.com/game-ci/unity-builder/issues/564#issuecomment-1892023344, I'm experiencing the following problem when trying to build my Unity project with `game-ci/unity-builder@v4`:

```
Warning: Fetch --unshallow caught: Error: Failed to run "git fetch --unshallow".
In-command error caught: Error: The process '/usr/bin/git' failed with exit code 128
Error: Failed to run "git fetch".
In-command error caught: Error: The process '/usr/bin/git' failed with exit code 128
```

**How to reproduce**

I'm not sure how to reproduce this, but this is a WebGL build if that matters.

**Expected behavior**

`game-ci/unity-builder` shouldn't fail to run `git fetch`. I wonder why it is running `git fetch` at all. Can anyone please provide details as to why it is and possibly how to avoid it?

**Additional information**

The GitHub action configuration looks like the following:

```yaml
- uses: game-ci/unity-builder@v4
env:
UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
UNITY_SERIAL: ${{ secrets.UNITY_SERIAL }}
with:
allowDirtyBuild: true
targetPlatform: WebGL
versioning: Semantic
```