Watcher is not working on builders

## Prerequisites

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

## Description

Builders are a common pattern used by developers on different use-cases: https://refactoring.guru/design-patterns/builder
The watcher's default ignore pattern is containing `build` which cause the watcher to ignore all the paths with `build` in them. In my case the problem went even further since my app name is `xy-builder` and during troubleshooting I've found out that the `watcher.getWatched()` will return with an empty object every time and the hot reload won't work at all.

## Steps to Reproduce

### Init
```bash
#!/bin/bash
mkdir test
cd test
npm init
npm i fastify-cli
npx fastify-cli generate any-builder
cd any-builder
npm i
```
### Add logging to debug
1. Under `node_modules/fastify-cli/lib/watch` open the `index.js` file
2. Add `console.log(watcher.getWatched())` to ln 83 (or under `watcher.on('ready', function () {`
3. Save the file

### Reproduce error
1. Run `npm run dev`
2. See that the `console.log()` output will be `{}`

### Screenshots:
1. The buggy behaviour

2. Temporary removed the build from the default ignoreWatch by hardcoding the defaults into `start.js` to showcase the expected results

## Expected Behavior

I think the expected behaviour here should be a match for build exactly. I'm a newbie to Fastify tho so I'm not sure where `build` folder will be important since as far as I see so far the ts build's default destination is `dist/` as well. If we are not using build folders on a purpose I think maybe we could remove it from the default ignores at all but please let me know about your thoughts on this topic.