Remove coef_ requirement from ONNX exporter.

[bogedy]

This PR is my attempt to solve the todo to make the ONNX exporter work with any sklearn model_head that doesn't have the coef_ attribute, which was deprecated for OneVsRestClassifier in sklearn 1.1.

I just use n_features_in_ for the shape and for the dtype I check if it has a coef_ attribute and if not I take the coef_ attribute of the first element of estimators_.

I also expanded the ONNX test file script.

This is my first PR on anything, my apologies if I misunderstood the scope of the problem or did anything else wrong!

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint.

[tomaarsen]

This is looking good! Especially for a first PR. However, I do have some notes/questions.
First of all, could you run make style to run some formatting rules, and then push those changes? This will satisfy the currently failing quality checks.

[bogedy]

Sorry, didn't realize that pushing to my own branch would update here. First PR...

[tomaarsen]

No worries! It'll all get squashed into one neat commit when I merge this, so you don't have to worry too much about keeping the PR "tidy" with few commits, etc. :)

[bogedy]

Don't know why the quality check isn't passing. I ran make style && make quality repeatedly and double checked that I had the right versions installed. I followed all the dev instructions. Passes on my machine.

[tomaarsen]

@bogedy

I ran the style locally, as I think my local black & isort versions align with the ones that the CI uses.
Do you think the PR is ready?

[bogedy]

Hi! I'm sorry I fell off this, got really busy. The PR is ready. I thought maybe I should upload a new model to hugging face since the lewtun my awesome model appears to be bugged with ONNX, but I suppose that can be taken care of later.

[bogedy]

I thought this needed a lot more and neglected it but looking at the error in the unit test it was just random chance?

502 Server Error: Bad Gateway for url: https://huggingface.co/lewtun/my-awesome-setfit-model/resolve/a3c0fe9302019e63581ad34ab25e6b6c5b4aab5d/pytorch_model.bin

That URL works for me...

[tomaarsen]

I get similar test failures here: #397. I haven't figured out how these started happening, as the Openvino version hasn't changed to my knowledge.

[bogedy]

I found the issue I think. It's hummingbird_ml-0.4.9. Downgrading to 0.4.8 makes the tests pass for me.

[tomaarsen]

I'll merge main into this so we can rerun the tests :)

[tomaarsen]

This is looking good I think! Thanks, and apologies for the delays and random CI issues. Oh, and thanks for fixing the latest CI issues for me!

[bogedy]

@tomaarsen thank you so much for holding my hand through my first ever PR, sorry I neglected it for months haha

[tomaarsen]

Haha no worries, it's also my bad for failing to review this PR for weeks or months. No big deal all around