Fix `pytorch_lightning` dependencies

[allemangD]

(Quoted from Slicer/ExtensionsIndex#1973 (comment))

pytorch_lightning fails to import even after it's been installed, which prevents loading the PlaneCNN module.

cannot import name 'get_num_classes' from 'torchmetrics.utilities.data' (site-packages/torchmetrics/utilities/data.py)

I suggest revisiting the pinned versions in your slicer.util.pip_install calls, and possibly add a pinned installation for torchmetrics.