to save and load variants
	
Saving a diffusion pipeline as a variant can be done by providing DiffusionPipeline.save_pretrained() with the variant argument.
The variant extends the weight name by the provided variation, by changing the default weight name from diffusion_pytorch_model.bin to diffusion_pytorch_model.{variant}.bin or from diffusion_pytorch_model.safetensors to diffusion_pytorch_model.{variant}.safetensors. By doing so, one creates