fix(graph): remove duplicate wo_s scale after build_attn (Qwen3, LLaMA)

[ynankani]

Overview

Observed that build_attn present in llama-graph already applies NVFP4 per tensor scale (wo_s) via
llama-graph.cpp (build_lora_mm(wo, cur, wo_s) or explicit wo_s mul).
Also observed these model builders(qwen3, qwen3moe, llama) are also multiplied the
result by wo_s again, so wo_s was applied twice whenever companion
blk.*.attn_output.scale tensors were present.
That crushed the attention residual (roughly wo_s^2 per layer) and broke
NVFP4 GGUFs for LLM_ARCH_QWEN3, LLM_ARCH_QWEN3MOE, and LLM_ARCH_LLAMA /
LLM_ARCH_LLAMA_EMBED.
Remove the redundant ggml_mul blocks in:

• src/models/qwen3.cpp
• src/models/qwen3moe.cpp
• src/models/llama.cpp
  Non-NVFP4 GGUFs keep wo_s == nullptr, so behavior is unchanged there.

Additional information

This issue was observed when running inference on https://huggingface.co/nvidia/Qwen3-8B-NVFP4 converted GGUF model

Requirements

• I have read and agree with the contributing guidelines
• AI usage disclosure: No

[CISC]

Ooops, nice catch. :)