描述bug

当将 @Moderate 注解添加到 @AiService 's方法时，会抛出异常，提示即使在 application.yml 文件中设置了建议的 moderation model 属性，但 moderation model 尚未配置。

日志和堆栈跟踪

dev.langchain4j.exception.IllegalConfigurationException: The @Moderate annotation is present, but the moderationModel is not set up. Please ensure a valid moderationModel is configured before using the @Moderate annotation.
	at dev.langchain4j.exception.IllegalConfigurationException.illegalConfiguration(IllegalConfigurationException.java:12)
	at dev.langchain4j.service.DefaultAiServices.build(DefaultAiServices.java:67)
	at dev.langchain4j.service.spring.AiServiceFactory.getObject(AiServiceFactory.java:90)

重现步骤

@AiService
public interface Assistant {

    @SystemMessage("""
            You are a polite assistant.
            """)
    @Moderate
    String assist(@UserMessage String message);

}

带有属性：

...
langchain4j:
  open-ai:
    chat-model:
      api-key: ${OPENAI_API_KEY}
      model-name: gpt-3.5-turbo
      temperature: 0.7
      log-requests: true
      log-responses: true
    moderation-model:
      api-key: ${OPENAI_API_KEY}

预期行为

moderation model 应自动配置，并且像聊天模型一样可以立即使用 moderation。

请填写以下信息：

• LangChain4j 版本：0.31.0
• 使用的 LLM(s):gpt-3.5-turbo
• Java 版本：17
• Spring Boot 版本(如适用):3.2.4
  其他上下文

看起来 dev.langchain4j.service.spring.AiServicesAutoConfig 在 aiServicesRegisteringBeanFactoryPostProcessor() 中缺少对 moderation model bean 的注册调用：

AiService aiServiceAnnotation = (AiService)aiServiceClass.getAnnotation(AiService.class);
addBeanReference(ChatLanguageModel.class, ...);
addBeanReference(StreamingChatLanguageModel.class, ...);
addBeanReference(ChatMemory.class, ...);
addBeanReference(ChatMemoryProvider.class, ...);
addBeanReference(ContentRetriever.class, ...);
addBeanReference(RetrievalAugmentor.class, ...);
addBeanReference(ModerationModel.class, ...); // <- this is missing!!