🐛 BUG: Wildcard is used after return of a more specific route

### What version of `Wrangler` are you using?

2.6.1

### What operating system are you using?

MacOS

### Describe the Bug

Using `wrangler pages dev .` and having the following file structure:

```

── functions
├── [[path]].js
├── _middleware.js
├── index.js
```

Consider `index.js` doing this:

```javascript
export async function onRequest(context) {
return new Response('Doing something on root index');
}
```

and `[[path]].js` this:
```javascript
export async function onRequest(context) {
return new Response('Doing something instead of 404 :-)');
}
```

Opening the root `http://127.0.0.1:8788/` will return the wildcard match (print: `'Doing something instead of 404 :-)'`).

I would expect to let the more specific route to "return its `new Response()`" but it's completely lost. This behavior should only be if one would call `context.next()` from `index.js`.