remove the workaround in TorchIO_MONAI_PyTorch_Lightning.ipynb

https://github.com/Project-MONAI/tutorials/blob/main/modules/TorchIO_MONAI_PyTorch_Lightning.ipynb

```
FIXME: Temporarily install PyTorch 1.10.2 during to PyTorchLightning issue: https://github.com/PyTorchLightning/pytorch-lightning/issues/10597
```

this currently changes the test environment when launching notebooks with `runner.sh `