Pool loses caller's AsyncLocalStorage context for queued HTTPS requests (Undici 8) #5981

Bug Description

Reproduction

Standalone reproduction script:

'use strict'

import { AsyncLocalStorage } from 'node:async_hooks'
import { subscribe } from 'node:diagnostics_channel'

const storage = new AsyncLocalStorage()

subscribe('undici:request:create', ({ request }) => {
  console.log(request.path, '→', storage.getStore())
})

await Promise.all(
  ['a', 'b', 'c'].map((name) =>
    storage.run(name, () => fetch(`https://example.com/${name}`)),
  ),
)

Steps to reproduce (if not using the script above):

Expected Behavior

/a → a
/b → b
/c → c

Every request dispatches in the async context of its own fetch() / request() caller, whether it was sent immediately or queued behind the connection probe.

Actual Behavior

/a → a
/b → a
/c → a

Same with request() from the undici package. Only https: origins are affected. http://example.com prints a, b, c correctly on the same version. Cause: Pool defers /b and /c until /a's connection finishes ALPN negotiation, then dispatches them from /a's connect callback, so they inherit /a's async context.

Logs & Screenshots

Environment

• OS:
• Node.js version:
• undici version:

Additional context

Discovered in a test failure in MSW (see job) after Undici introduced changes in Node.js v26 (passes in v22 and v24).