PyTorch dependency

[gtdang]

PR #394 Is failing because because the Linux build is looking for GPU modules and the GitHub workflow actions instances don't have GPUs.

This occurs because the pip install torch behave differently between operating systems. See PyTorch installation guide

• On Linux it will default to the GPU version. To opt out, you must provide the URL to the CPU version.
• On Mac/Windows it will default to the CPU version. You must provide the URL to the GPU version if you want it.

To fix this we will need to update the pyproject.toml file to have conditional downloads based on the operating system.