Dev server process not terminated by SIGINT when loader is stuck

### Have you read the Contributing Guidelines on issues?

- [X] I have read the [Contributing Guidelines on issues](https://github.com/facebook/docusaurus/blob/main/CONTRIBUTING.md#reporting-new-issues).

### Prerequisites

- [X] I'm using the latest version of Docusaurus.
- [X] I have tried the `npm run clear` or `yarn clear` command.
- [X] I have tried `rm -rf node_modules yarn.lock package-lock.json` and re-installing packages.
- [ ] I have tried creating a repro with https://new.docusaurus.io.
- [ ] I have read the console error message carefully (if applicable).

### Description

If the loader has an infinite loop or any other bug that causes it to get stuck, the dev server keeps running even when SIGINT is sent.

Discovered while working on https://github.com/facebookincubator/infima/pull/219

### Reproducible demo

_No response_

### Steps to reproduce

1. Init
2. Change the options:

```js
docs: {
sidebarPath: require.resolve('./sidebars.js'),
// A hopeless infinite loop
remarkPlugins: [() => { while (true); }],
},
```

3. `yarn start`
4. Oh no, page stuck. SIGINT (Ctrl + C) to the rescue
5. `yarn start` again
6. `[WARNING] Something is already running on port 3000. Probably:`
7. What? Run `lsof -i tcp:3000` => The dev server process is indeed still running
8. Use the force: `kill -9 47874`

### Expected behavior

SIGINT should be able to stop the dev server

### Actual behavior

It keeps running in the background and listening on port 3000. Probably the `compile` process is never hung properly...

### Self-service

- [X] I'd be willing to fix this bug myself.