fix(autonat-v2): apply timeout to verification requests

[kediyalua]

Title

fix(autonat-v2): apply timeout to verification requests

Description

AutoNATv2Client.verifyExternalAddresses() creates a combined abort signal for
every queued verification job:

const signal = anySignal([options.signal, AbortSignal.timeout(this.timeout)])

...but then passes the original options object to askPeerToVerify() instead
of that signal, so the only thing the combined signal is used for is
signal.clear() in the finally block. As a result the timeout option
(TIMEOUT = 30s by default) never applied to the client side of the AutoNAT v2
exchange: connection.newStream(), messages.write() and messages.read()
could all block forever if the remote accepted the stream but never answered.

This looks like an oversight rather than a design decision - the surrounding
anySignal(...) / signal.clear() scaffolding only makes sense if the signal is
actually used, and the rest of the module does use its timeout signals
(handleDialBackStream() applies AbortSignal.timeout(this.timeout) to its
reads/writes, findRandomPeers() passes its combined signal to
randomWalk.walk() and openConnection()).

The fix forwards the combined signal to askPeerToVerify():

await this.askPeerToVerify(connection, segment, nonce, {
  ...options,
  signal
})

setMaxListeners(Infinity, signal) is added for consistency with
kad-dht/src/query/manager.ts - the signal is now listened to by every stream
operation performed by the job.

A regression test is included: it configures the service with the existing 100ms
timeout and uses a remote that accepts the dial-request stream but never sends
a DialResponse. Before the fix the stream stays open forever and the test
fails; after the fix the stream is aborted shortly after the timeout elapses.

Fixes https://github.com/libp2p/js-libp2p/issues/ISSUE_NUMBER

Notes & open questions

• While writing the test I noticed the existing
  should time out when verifying an observed address case asserts
  addressManager.addObservedAddr was not called, but the AutoNAT v2 client only
  ever calls confirmObservedAddr / removeObservedAddr, so that assertion is
  trivially true and the case does not actually exercise any timeout behaviour.
  I left it untouched to keep this PR focused - happy to fix or remove it in a
  follow-up if you prefer.
• Separately, findRandomPeers() builds an anySignal that is never
  clear()ed, which leaves its 10s AbortSignal.timeout() timer alive. Not
  addressed here; say the word and I'll include it.

Change checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation if necessary (this includes comments as well)
• I have added tests that prove my fix is effective or that my feature works