v3: Nitro doesnt send correct response when throwing errors

Reproduction

https://github.com/MickL/nitro-ofetch-bug

Describe the bug

When throwing an error, the frontend does never receive a response, e.g.:

import {defineHandler, HTTPError} from "nitro";

export default defineHandler((event) => {
    throw new HTTPError({
        status: 401,
        message: 'hello world',
    });
});

In separate frontend app:

import { ofetch } from "ofetch";

await ofetch(`http://localhost:3000/hello`, {
      onRequest(context) {
        console.log('onRequest');
      },
      onRequestError(context) {
        console.log(context.error);
        console.log('onRequestError');
      },
      onResponse(context) {
        // This never gets called <------
        console.log('onResponse: ' + context.response.status);
      },
      onResponseError(context) {
        // This never gets called <------
        console.log('onResponseError: ' + context.response.status);
      },
});

Start with the linked reproduction at https://github.com/MickL/nitro-ofetch-bug and trace Nitro's handling of the HTTPError thrown by defineHandler. Verify the frontend receives the server response and that the relevant ofetch response callback is invoked with the 401 status and error message shown in the issue.