support StableDiffusionAdapterPipeline.from_single_file

[Teriks]

What does this PR do?

Adds support for from_single_file to StableDiffusionAdapterPipeline by inheriting FromSingleFileMixin

importdiffusersfromPILimportImagefromdiffusers.utilsimportload_imageimporttorch# checkpoint: https://civitai.com/api/download/models/74821?type=Model&format=SafeTensor&size=pruned&fp=fp16image=load_image(
"https://huggingface.co/datasets/diffusers/docs-images/resolve/main/t2i-adapter/color_ref.png"
)
color_palette=image.resize((8, 8))
color_palette=color_palette.resize((512, 512), resample=Image.Resampling.NEAREST)
adapter=diffusers.T2IAdapter.from_pretrained("TencentARC/t2iadapter_color_sd14v1", torch_dtype=torch.float16)
# single file loadpipe=diffusers.StableDiffusionAdapterPipeline.from_single_file(
'impressionismOil_sd15.safetensors',
adapter=adapter, torch_dtype=torch.float16)
pipe.to('cuda')
output=pipe(
prompt='impressionist oil painting of a sunset', image=color_palette).images[0]
output.save('test.png')

Previously working around this with:

pipe_class=type(
'StableDiffusionAdapterPipeline', (diffusers.loaders.FromSingleFileMixin, diffusers.StableDiffusionAdapterPipeline), {})

Fixes#9123

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline?
• Did you read our philosophy doc (important for complex PRs)?
• Was this discussed/approved via a GitHub issue or the forum? Please add a link to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

@DN6

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[Teriks]

@yiyixuxu