Pytorch RCFR issue with Python 3.13 

PyTorch RCFR test sometimes failing on Python 3.13, PyTorch 2.6.0.

```
  File "rcfr.py", line ***, in _walk_descendants
    reach_probabilities[player] = next_reach_prob
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^
ValueError: setting an array element with a sequence.
```

Test will be disabled for now.