Fixes#61495
When manually triggering cron jobs from a live Matrix session, delivery
would fail with "Timeout context manager should be used inside a task"
because the aiohttp.ClientTimeout context manager requires a proper asyncio
task context.
Use asyncio.wait_for() instead of aiohttp.ClientTimeout to avoid this error,
following the same pattern as the Weixin platform (gateway/platforms/weixin.py).
Changes:
- Remove aiohttp.ClientTimeout(total=30) from ClientSession constructor
- Wrap the send operation in a nested async function (_do_send)
- Use asyncio.wait_for(_do_send(), timeout=30) for timeout handling
- Catch asyncio.TimeoutError explicitly and return clear error message
358d55051e