Unet's "Groups" is unused

[torridgristle]

It seems that "groups" for the Unet aren't used. It's not passed to the ResNetBlock modules nor the Block in the final_conv.

[lucidrains]

@torridgristle ohh yea, that's for the groupnorms - but i think i will be replacing the resnet blocks with the new convnext ones and aim for all layernorms

[lucidrains]

ok done! no more groups and groupnorms!