Exclude audio modules from conversion process
Author: softguy777
Pull request: yes

Add logic to exclude audio modules from conversion to prevent uint8 crash in multimodal models.

As discussed in the issue, this prevents the torch.finfo() TypeError on uint8 weights during 4-bit inference for multimodal models like Gemma 4, and preserves audio encoder fidelity.

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Fixes #45672, Fixes #45674

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Comments:
cc @sunmarc

@SunMarc Thanks for the review! Sorry for the delay — I've addressed your feedback:

- Updated the comment to reflect that audio modules are small and not worth quantizing
- Changed to `named_children()` so only top-level modules are added
- Added a test in `tests/quantization/bnb/test_4bit.py`

Please let me know if anything else needs to be changed!


@bot /style 

Style fix bot fixed some files and pushed the changes.

**[For maintainers]** Suggested jobs to run (before merge)

run-slow: zamba2, bnb

Can you try to rebase on main to fix the CI, I'll merge this afterwards @softguy777, thanks a lot ! 

Hi, a small quick question, does this PR fix issue #45672 and #45674 together? Thanks!