[Bugfix] EPLB verify

[shenchuxiaofugui]

What this PR does / why we need it?

When the dtype of the MTP layer is fp16, this layer does not go through EPLB. However, the EPLB check in the verification process is applied uniformly to the entire model, and it still checks whether the dtype is w8a8. Currently, whether to use EPLB is determined separately for each layer.

Does this PR introduce any user-facing change?

No

How was this patch tested?

[github-actions]

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[gemini-code-assist]

Code Review

This pull request addresses a bug in the Expert Parallel Load Balancing (EPLB) verification. The change correctly restricts the quantization method check to static EPLB configurations (those using expert_map_path), resolving an issue where dynamic EPLB was incorrectly constrained. The implementation is sound and the fix is effective. The changes look good.