qwen3.5 router_aux_loss_coef from the parser is not set

### Reminder

- [x] I have read the above rules and searched the existing issues.

### System Info

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### Reproduction

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### Others

https://github.com/hiyouga/LlamaFactory/blob/e67ab9e2f2c924a459b8586e3370b01dd5734b36/src/llamafactory/model/model_utils/moe.py#L158

`qwen3_5_moe` is not specified.