build(deps): bump dubbo

Bumps [dubbo](https://github.com/apache/dubbo) from 2.7.13 to 2.7.21.
- [Release notes](https://github.com/apache/dubbo/releases)
- [Changelog](https://github.com/apache/dubbo/blob/3.2/CHANGES.md)
- [Commits](apache/dubbo@dubbo-2.7.13...dubbo-2.7.21)

---
updated-dependencies:
- dependency-name: org.apache.dubbo:dubbo
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

dongtai-api-gather/dongtai-api-gather-dubbo-api/pom.xml

@@ -16,7 +16,7 @@
             <groupId>org.apache.dubbo</groupId>
             <artifactId>dubbo</artifactId>
             <!--  不要修改这个依赖版本，如果必须改动需要保证在 [2.7.13, 3.0.0) 区间 -->
-            <version>2.7.13</version>
+            <version>2.7.21</version>
             <scope>provided</scope>
         </dependency>
         <dependency>