Cannot detect `@swc-node/register` loaded by `fastify-cli` with the `-r` option

### 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

4.28.1

### Plugin version

5.10.0

### Node.js version

20.x

### Operating system

Windows

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

10

### Description

I'm using `fastify start -r @swc-node/register app.ts` to start my app written in TypeScript.

However, this plugin cannot detect `@swc-node/register` loaded by `fastify-cli` and the following error is thrown:

```console
Error: @fastify/autoload cannot import plugin at '~/fastify-app/plugins/sensible.ts'. To fix this error compile TypeScript to JavaScript or use
'ts-node' to run your app.
```

**Related PR:**

PR https://github.com/fastify/fastify-autoload/pull/191 fixed the case with `node -r @swc-node/register` but not with `fastify start -r @swc-node/register`.

**Current workaround:**

I have to manually set the `FASTIFY_AUTOLOAD_TYPESCRIPT` environment variable.

**Additional information:**

The current `checkPreloadModules()` util checks the `process._preload_modules` array, but it's empty when the package is required with `fastify-cli`.

### Link to code that reproduces the bug

https://github.com/zetaraku/fastify-app

### Expected Behavior

The plugin should be able to detect the `@swc-node/register` package loaded by `fastify start -r @swc-node/register`.