support Qwen3-MoE-w4afp8

[zhilingjiang]

Motivation

Follow #8118. Base on #7762.

Modifications

This PR primarily implements the adaptation of SGLang for Qwen3-MoE-w4afp8 quantized models. The key enhancements include:

Support for Qwen3-MoE’s w4afp8-block quantization format: SGLang can now load and run models that have been quantized using the w4afp8-block format.
Support for loading Qwen-MoE static quantization calibration parameters: SGLang is now capable of loading and utilizing the static quantization calibration parameters for Qwen-MoE models, ensuring correct inference behavior after quantization.

Accuracy Tests

You can download the Qwen3-30B-A3B-w4afp8-block model here.
https://huggingface.co/zhilingjiang/Qwen3-30B-A3B-w4afp8-block-dynamic

Checklist

• Format your code according to the Format code with pre-commit.
• Add unit tests according to the Run and add unit tests.
• Update documentation according to Write documentations.
• Provide accuracy and speed benchmark results according to Test the accuracy and Benchmark the speed.

[gemini-code-assist]

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[ZhuJiaqi9905]

Hi, it is a nice work. However, it seems that there are too many diff in the git commit. Could you please fix it to help us understand your code? I think that in order to support Qwen-235B-w4afp8 in TP mode, we should special handling "weight interleave scales" which should not be 4, and modify the sgl-kernel.