Update pipeline_flux_img2img.py

[example-git]

What does this PR do?

Added FromSingleFileMixin to this pipeline loader like the other FLUX pipelines. (So this pipeline can load from an all in one checkpoint file)

def load_img2img() -> FluxImg2ImgPipeline:
    """Load the pre-trained img2img pipeline."""
    pipeline = FluxImg2ImgPipeline.from_single_file(checkpoint_location, torch_dtype=torch.bfloat16
    ).to("cuda")
    return pipeline
pipeline = load_img2img()

can be used to test it if you have a flux checkpoint with other models mixxed into it, it works now after that change though from my tests

@yiyixuxu and @asomoza

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?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

[asomoza]

thanks @example-git, can you please update the branch and run make quality and make style please

[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.

[example-git]

@asomoza done

[asomoza]

thanks a lot