Revert "[Diffusion] Add FLUX.1-dev ModelOpt NVFP4 support (#22574)"

[mickqian]

This reverts commit 03a1a7b #22574

failed ci: https://github.com/sgl-project/sglang/actions/runs/24322506533/job/71011288001?pr=22633

Motivation

Modifications

Accuracy Tests

Speed Tests and Profiling

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.
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[mickqian]

/tag-and-rerun-ci

[gemini-code-assist]

Code Review

This pull request simplifies the ModelOpt quantization workflow by removing the NVFP4 mixed-precision builder, hardcoding nibble swapping, and renaming the FP8 conversion tool to convert_modelopt_fp8_checkpoint. It also removes the prefix argument from several linear layer initializations within the FLUX model. Feedback indicates that the removal of the prefix argument is inconsistent in FluxAttention, which could lead to runtime errors, and suggests removing the now-unused prefix parameter from the FluxSingleTransformerBlock constructor.

[gemini-code-assist]

While this revert correctly removes the prefix argument from this ColumnParallelLinear call, other calls within FluxAttention (e.g., for to_out and to_add_out) still use the prefix argument. This suggests an incomplete revert. If ColumnParallelLinear no longer accepts prefix after this revert, those calls will cause a runtime error. Please ensure the prefix argument is removed from all ColumnParallelLinear calls consistently.

[gemini-code-assist]

This change, along with other similar changes in this block, makes the prefix parameter of FluxSingleTransformerBlock.__init__ unused. Please consider removing the prefix parameter from the method signature in a follow-up change to improve code clarity.