Apache Beam tests are failing

From https://github.com/cubed-dev/cubed/actions/runs/17928571700/job/50980650239:

```
FAILED cubed/tests/test_executor_features.py::test_callbacks[beam] - KeyError: 'peak_measured_mem_start'
FAILED cubed/tests/test_executor_features.py::test_callbacks_as_context_managers[beam] - assert 0 == (1 + 4)
 +  where 0 = <cubed.tests.utils.TaskCounter object at 0x7f7ee074a690>.value
```