* test: add unit tests for DanglingToolCallMiddleware
Cover message patching logic for dangling tool calls:
- No-op when all tool calls have responses
- Synthetic ToolMessage insertion at correct positions
- Mixed responded/dangling scenarios
- wrap_model_call and awrap_model_call integration
* test: fix async tests and strengthen override assertions
- Use @pytest.mark.anyio + async def instead of deprecated
asyncio.get_event_loop().run_until_complete() (fixes Py3.12 CI failure)
- Assert that override() receives the correct patched messages kwarg
in both wrap_model_call and awrap_model_call tests
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Co-authored-by: Willem Jiang <willem.jiang@gmail.com>
