[Bug] The link to the model is incorrect in the GitHub Actions environment.

- I didn't find a similar issue already open.
- I read the documentation (README AND Wiki)
- I have installed FFMpeg
- My problem is related to Spleeter only, not a derivative product (such as Webapplication, or GUI provided by others)
- I have found the specific location of the relevant code.

## Description

I ran the `spleeter separate` command in an Ubuntu environment using GitHub Actions, but encountered an error. The issue lies in the incorrect download link for the model.

The information is
```bash
httpx.HTTPStatusError: 404 Client Error: Not Found for url: https://github.com/pansong291/github-action-tasks/releases/download/v1.4.0/2stems.tar.gz
```

And the code looks like
```python
return cls(
environ.get("GITHUB_HOST", cls.DEFAULT_HOST),
environ.get("GITHUB_REPOSITORY", cls.DEFAULT_REPOSITORY),
environ.get("GITHUB_RELEASE", cls.LATEST_RELEASE),
)
```

I suspect that this issue may be caused by the presence of a duplicate variable with the same name in the environment variables of GitHub Actions.

## Step to reproduce

1. A different github repo
2. Use the Github Actions
3. Got 404 error

## Output

```bash
httpx.HTTPStatusError: 404 Client Error: Not Found for url: https://github.com/pansong291/github-action-tasks/releases/download/v1.4.0/2stems.tar.gz
```

## Environment

| | |
| ----------------- | ------------------------------- |
| OS | Linux (Ubuntu) |
| Installation type | pip |
| RAM available | -- |
| Hardware spec | CPU |

## Additional context