参考：
https://github.com/huggingface/blog/blob/main/quanto-diffusers.md
安装
pip install optimum-quanto
%pip install optimum
使用
from optimum.quanto import freeze, qfloat8, quantize
from diffusers import PixArtSigmaPipeline
import torchpipeline = PixArtSigmaPipeline.from_pretrained
