[Misc] Refactor ops

[wangxiyuan]

1. remove useless function vanilla_chunked_prefill_mla, vanilla_decode_mla, causal_conv1d_update_ref and rms_norm_ref
2. move expert_load_balancer to eplb module
3. move fla, casual_conv1d and sigmoid_gating to triton module

• vLLM version: v0.10.2
• vLLM main: vllm-project/vllm@c60e613

[github-actions]

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[gemini-code-assist]

Code Review

This pull request is a good refactoring effort that improves the project structure by moving modules to more logical locations and removing apparently unused functions. The changes are consistent with the description, leading to a cleaner codebase. However, I've identified a critical issue in vllm_ascend/ops/__init__.py where significant changes to the package's public API are made by removing several imports and the __all__ definition. These changes could break other parts of the codebase or downstream consumers and are not documented in the pull request. Please address this to ensure the stability of the package's API.

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.