aiohttp timeout and wrapped google-auth transport exceptions are not retried despite HttpRetryOptions being configured #3329

Describe the bug

When HttpRetryOptions is configured and aiohttp is used as the async HTTP transport (google-genai[aiohttp]), request timeouts and wrapped google.auth.aio transport exceptions bypass retry_args() and fail on the first attempt without retrying.

Specifically:

1. asyncio.TimeoutError (and aiohttp.ServerTimeoutError / aiohttp.ConnectionTimeoutError):
   While _HTTPX_TRANSIENT_EXC includes httpx.TimeoutException and httpx2.TimeoutException (added in fix(retry): retry on httpx.TimeoutException with HttpRetryOptions #2345 for httpx.TimeoutException is not retried despite HttpRetryOptions being configured #2337), _AIOHTTP_TRANSIENT_EXC only lists (aiohttp.ClientConnectorError, aiohttp.ClientOSError, aiohttp.ServerDisconnectedError). In aiohttp, ClientTimeout(total=...) (TimerContext.__exit__) raises asyncio.TimeoutError directly, and aiohttp.ServerTimeoutError / ConnectionTimeoutError inherit from (aiohttp.ClientConnectionError, asyncio.TimeoutError), not ClientConnectorError, ClientOSError, or ServerDisconnectedError.
2. google.auth.exceptions.TimeoutError (auth_exceptions.TimeoutError):
   When Vertex AI mTLS is used (_use_google_auth_async() == True), _get_aiohttp_session() returns google.auth.aio.transport.sessions.AsyncAuthorizedSession. Both google.auth.aio.transport.aiohttp.Request.__call__ and google.auth.aio.transport.sessions.timeout_guard catch asyncio.TimeoutError and raise google.auth.exceptions.TimeoutError (which inherits from GoogleAuthError, not builtins.TimeoutError or aiohttp.ClientError).
3. google.auth.exceptions.TransportError wrapping _AIOHTTP_TRANSIENT_EXC:
   Under AsyncAuthorizedSession, google.auth.aio.transport.aiohttp.Request.__call__ catches aiohttp.ClientError and raises google.auth.exceptions.TransportError(...) from caught_exc. In _async_request_once(), the except (..., auth_exceptions.TransportError) block re-raises when retry_options is configured (raise # HttpRetryOptions owns retries; tenacity decides.), but retry_args() does not match auth_exceptions.TransportError wrapping _AIOHTTP_TRANSIENT_EXC.

Steps to reproduce

import asyncio
from google.auth import exceptions as auth_exceptions
from google.genai import _api_client as api_client
from google.genai import types
import aiohttp

retry = api_client.retry_args(types.HttpRetryOptions())['retry']
print("asyncio.TimeoutError retried:", retry.predicate(asyncio.TimeoutError()))
print("aiohttp.ServerTimeoutError retried:", retry.predicate(aiohttp.ServerTimeoutError()))
print("google.auth.exceptions.TimeoutError retried:", retry.predicate(auth_exceptions.TimeoutError("Request timed out")))

Output on main:

asyncio.TimeoutError retried: False
aiohttp.ServerTimeoutError retried: False
google.auth.exceptions.TimeoutError retried: False

Expected behavior

When HttpRetryOptions is configured, retry_args() should retry asyncio.TimeoutError (including aiohttp.ServerTimeoutError and aiohttp.ConnectionTimeoutError), google.auth.exceptions.TimeoutError, and google.auth.exceptions.TransportError whose __cause__ is in _AIOHTTP_TRANSIENT_EXC, matching the httpx.TimeoutException behavior from #2337 / #2345 while keeping non-transient errors (such as aiohttp.ClientPayloadError and google.auth.exceptions.RefreshError) and the no-retry_options path unchanged.