Timeout breaking change

The bug was introduced in v6.20, the timeout that is set less than a second is ignored, Its a breaking change in minor version

server

const Fastify = require('fastify')
const fastify = Fastify()

fastify.all('*', async (req, reply) => {
  await new Promise((resolve) => setTimeout(resolve, 500))
  return reply.status(200).send(req.url)
});


fastify.listen({ port: 3000 })

client

const undici = require('undici')

undici.request('http://localhost:3000', {
  headersTimeout: 300,
}).then((response) => {
  console.log(response.statusCode)
})

Start with the provided Fastify server and undici.request reproduction, then trace the client timeout handling that is triggered by headersTimeout. Confirm the behavior for a timeout below one second and identify the existing timeout tests, if any; done means the reported sub-second timeout is honored without changing other timeout behavior.