ProxyAgent will cause customized host to reset

[1zilc]

Bug Description

ProxyAgent causes headers.host to be forcibly reset in undici.request

Reproducible By

undici.request('http://127.0.0.1:8000', {
  headers: {
    host: 'test.com',
  },
  dispatcher: new ProxyAgent({
    uri: 'http://127.0.0.1:1087',
  }),
});

Expected Behavior

request.headers.host should be test.com instead of 127.0.0.1:8000

Logs & Screenshots

Environment

macOS 14.4.0
node v20.11.0
undici 6.10.2

Additional context

without proxy

undici.request('http://127.0.0.1:8000', {
  headers: {
    host: 'test.com',
  },
});

[metcoder95]

Thanks for the report, would you like to submit a PR for it?

[1zilc]

I'd love to try and fix it.