skip fusedmoe layer for start_load_kv

[calvin0327]

Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.

Purpose

fix: #21359

Test Plan

Test Result

(Optional) Documentation Update

[gemini-code-assist]

Code Review

This pull request correctly addresses a crash that occurs when using FusedMoE layers with KV cache transfer by skipping layers that lack a kv_cache attribute. The fix is logical and directly solves the reported issue.

I've added one critical comment to enhance the robustness of the fix. The current implementation using hasattr could still lead to a TypeError if the kv_cache attribute exists but is None. My suggestion is to use getattr for a more defensive check that handles both missing attributes and None values, preventing potential runtime crashes.

[github-actions]

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[calvin0327]

@DarkLight1337 @KuntaiDu PTAL, thanks

[Abirdcfly]

Thanks, test this pr by model Qwen3-30B-A3B

[KuntaiDu]

This PR LGTM.

The code is overlapping with #21428 but it's for a different connector. Maybe we can deduplicate the code in the future.