[Model] use AutoWeightsLoader for phimoe,qwen2_moe,qwen3_moe

[lengrongfu]

FIX #15697

• Qwen3MoeForCausalLM
  Because can't download Qwen/Qwen3-MoE-15B-A2B this model, so not test.

• Qwen2MoeForCausalLM

$ python3 -m vllm.entrypoints.cli.main serve Qwen/Qwen1.5-MoE-A2.7B-Chat --trust-remote-code

• PhiMoEForCausalLM

$ python3 -m vllm.entrypoints.cli.main serve microsoft/Phi-3.5-MoE-instruct --trust-remote-code

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