Fix: Use NormalizedTextConfigWithGQA for Qwen3 model

[Aznix07]

What does this PR do?

Fixes the Qwen3 model condfiguration to use NormalizedTextConfigWithGQA instead of NormalizedTextConfig.

Problem

Qwen3 models use Group Query Attention (GQA) architecture similar to Qwen2, with:

• num_attention_heads: 16
• num_key_value_heads: 8
• head_dim: 128

The previous configuration used NormalizedTextConfig which does not have the num_key_value_heads attribute needed for GQA models, which causing:

1. Incorrect head dimension calculations (64 instead of 128)
2. ONNX export failures with error

Solution

Changed the normalized config class for qwen3 from NormalizedTextConfig to NormalizedTextConfigWithGQA in otimum/utils/normalized_config.py (line 314).

Testing

✅ Tested with Qwen/Qwen3-0.6B - all assertions passed:

• Correct normalized config class
• head_dim = 128
• GQA structure validated

Fixes #2379

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests?

Note: This is a configuration fix. No user-facing documentation changes needed. Manually verified the fix works correctly with Qwen3 models.

Who can review?

@echarlaix @JingyaHuang @michaelbenayounIlyasMoutawwakil

[IlyasMoutawwakil]

Hi ! Thanks for the catch ! what are the tests you ran exactly ? should this not be done on in optimum-onnx on the config level in https://github.com/huggingface/optimum-onnx/blob/c3db0acb978a916cf418350272242bb817276758/optimum/exporters/onnx/model_configs.py#L491

[HuggingFaceDocBuilderDev]

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