feat: optimize runtime performance by reducing copy input attachment.

[yq33victor]

No description provided.

[yq33victor]

The test is passed.

curl http://localhost:9977/v1/chat/completions   -H "Content-Type: application/json"   -d '{
    "model": "Qwen2-7B-Instruct",
    "max_tokens": 10,
    "temperature": 0,
    "stream": true,
    "messages": [
      {
        "role": "system",
        "content": "You are a helpful assistant."
      },
      {
        "role": "user",
        "content": "hello xllm"
      }
    ],
    "xxxx": "xxx",   # ===> unknow fileds will be ignored
    "yyy":true         # ===> unknow fileds will be ignored
  }'