watch mode not working with git worktree

### Prerequisites

- [X] I have written a descriptive issue title
- [X] I have searched existing issues to ensure the bug has not already been reported

### Fastify version

4.0.0

### Plugin version

_No response_

### Node.js version

16.17.0

### Operating system

Linux

### Operating system version (i.e. 20.04, 11.3, 10)

20.04

### Description

At #547, I mistakenly assumed that watch mode was not working because of esm, in fact, watch mode is not working if the project is in the **git worktree**.
If you use typescript, then typescript rebuilds the project, but the server still does not restart.

### Steps to Reproduce

```
git clone https://github.com/railwayapp-templates/fastify --bare
cd fastify.git
git worktree add main
cd main
npm i
npm run dev
```
change any file -> typescript rebuild -> server does not restart

### Expected Behavior

_No response_