Merge pull request #147 from aliyun/dependabot/maven/microservice-doc-demo/dubbo-samples-api/dubbo-api-provider/org.apache.dubbo-dubbo-2.7.21

Bump dubbo from 2.7.18 to 2.7.21 in /microservice-doc-demo/dubbo-samples-api/dubbo-api-provider

Author: ralf0131

microservice-doc-demo/dubbo-samples-api/dubbo-api-provider/pom.xml

@@ -24,7 +24,7 @@
         <dependency>
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo</artifactId>
-            <version>2.7.18</version>
+            <version>2.7.21</version>
         </dependency>
         <dependency>
             <groupId>com.alibaba.nacos</groupId>