### Environment

* Dubbo version: 3.0

### Steps to reproduce this issue
测试dubbo-samples项目的AnnotationServicesIT.testGreeting方法时，偶尔会出现服务端超时触发此异常。
手工触发方法：
修改AnnotationAction.java的greetingService服务引用对象的method超时注解，从3000改为1000（服务端代码里有2000毫秒sleep），然后运行就会遇到NPE：
```
java.lang.NullPointerException 
	at org.apache.dubbo.rpc.protocol.dubbo.DecodeableRpcResult.decode(DecodeableRpcResult.java:85)
```
DecodeableRpcResult 85行代码：```if (invocation.getServiceModel() != null) { ```
服务端超时，此处invocation为null。
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package org.apache.dubbo.rpc.protocol.dubbo;
import org.apache.dubbo.common.config.ConfigurationUtils;
import org.apache.dubbo.common.logger.Logger;
import org.apache.dubbo.common.logger.LoggerFactory;