Incorrect version and missing package in requirements.txt

[SoftologyPro]

These 2 fixes are needed in requirements for the app.py to launch without errors...

huggingface-hub needs to be 0.23.0 or greater otherwise running app.py gives
ImportError: cannot import name 'split_torch_state_dict_into_shards' from 'huggingface_hub'

No fastai in requirements
pip install fastai

[SoftologyPro]

Also saving as PNG rather than webp would be more compatible.