test: ignore branch-only arc in pytest.raises

Author: Epochex

tests/client/test_resource_cleanup.py

@@ -52,7 +52,7 @@ async def mock_send(*args: Any, **kwargs: Any):
     # Run the test with the patched method
     async with session:
         with patch.object(session._write_stream, "send", mock_send):
-            with pytest.raises(RuntimeError, match="Simulated network error"):
+            with pytest.raises(RuntimeError, match="Simulated network error"):  # pragma: no branch
                 await session.send_request(request, EmptyResult)
 
     # Verify that no response streams were leaked