Exiting `start` process duplicates terminal output

### Pre-flight checklist

- [x] I have read the [contribution documentation](https://github.com/electron/forge/blob/main/CONTRIBUTING.md) for this project.
- [x] I agree to follow the [code of conduct](https://github.com/electron/electron/blob/main/CODE_OF_CONDUCT.md) that this project uses.
- [x] I have searched the issue tracker for a bug that matches the one I want to file, without success.

### Forge version

v7.8.0

### Electron version

36.0.0

### Operating system

macOS Sequoia

### Last known working Forge version

v6.0.0-beta.70

### Expected behavior

When interrupting the `start` command, there should be no duplicate output.

### Actual behavior

After pressing Ctrl + C, the terminal output

```
yarn start
yarn run v1.22.22
$ electron-forge start
✔ Checking your system
✔ Locating application
✔ Loading configuration
✔ Preparing native dependencies [0.1s]
✔ Generating assets

^C✔ Checking your system
✔ Locating application
✔ Loading configuration
✔ Preparing native dependencies [0.1s]
✔ Generating assets
```

### Steps to reproduce

With any template, just `npm start` and press Ctrl + C to terminate the Forge process.

### Additional information

This seems to be caused by our migration from `async-ora` to `listr2` (https://github.com/electron/forge/pull/3022).

However, I'm unable to repro with Listr2's base examples, so I think the problem is with our implementation.