Update with definitely right requirements for skimage

In my defense I was doing this on my phone.

requirements.txt

@@ -10,7 +10,7 @@ omegaconf
 pytorch_lightning
 diffusers
 invisible-watermark
-scikit-image>=0.1.9
+scikit-image>=0.19
 fonts
 font-roboto
 git+https://github.com/crowsonkb/k-diffusion.git