Support PyTorch v2.2.0

[pgleeson]

Current development is limited to torch<2.2.0. Issue with latest version, e.g.

https://github.com/ModECI/MDF/actions/runs/7738901064/job/21100655263

         # Call out to a part of the ONNX exporter that simiplifies the graph before ONNX export.
        from torch.onnx.utils import _model_to_graph
        from torch.onnx import TrainingMode
>       from torch.onnx.symbolic_helper import _set_opset_version
E       ImportError: cannot import name '_set_opset_version' from 'torch.onnx.symbolic_helper' (/opt/hostedtoolcache/Python/3.11.7/x64/lib/python3.11/site-packages/torch/onnx/symbolic_helper.py)

/opt/hostedtoolcache/Python/3.11.7/x64/lib/python3.11/site-packages/modeci_mdf/interfaces/pytorch/importer.py:526: ImportError