[BUG] AsyncTwilioHttpClient.request does not use self.timeout

Describe the bug

AsyncTwilioHttpClient.request never falls back to self.timeout if timeout is None

Code snippet

        if timeout is not None and timeout <= 0:
            raise ValueError(timeout)

        basic_auth = None
        if auth is not None:
            basic_auth = BasicAuth(login=auth[0], password=auth[1])

        kwargs = {
            "method": method.upper(),
            "url": url,
            "params": params,
            "data": data,
            "headers": headers,
            "auth": basic_auth,
            "timeout": timeout,
            "allow_redirects": allow_redirects,
        }

        self.log_request(kwargs)
        self._test_only_last_response = None

        temp = False
        session = None
        if self.session:
            session = self.session
        else:
            session = ClientSession()
            temp = True
        self._test_only_last_request = TwilioRequest(**kwargs)
        response = await session.request(**kwargs)

Actual behavior

response is passed "timeout": None in kwargs instead of "timeout": self.timeout when no timeout argument is passed

Expected behavior

response is passed "timeout": self.timeout in kwargs when no timeout argument is passed, this is what (sync) TwilioHttpClient does:

        if timeout is None:
            timeout = self.timeout
        elif timeout <= 0:
            raise ValueError(timeout)

twilio-python version

9.10.9

Python version

3

Logs or error messages

No response

Additional context

No response

Start at the AsyncTwilioHttpClient.request entry point shown in the issue and compare its timeout handling with TwilioHttpClient.request. Check the existing tests for these clients before making the change. Done means a missing timeout uses self.timeout while nonpositive explicit values still raise ValueError, with coverage for both cases.