Bump gson from 2.8.4 to 2.8.9 in /pack-dependencies

Bumps [gson](https://github.com/google/gson) from 2.8.4 to 2.8.9.
- [Release notes](https://github.com/google/gson/releases)
- [Changelog](https://github.com/google/gson/blob/master/CHANGELOG.md)
- [Commits](https://github.com/google/gson/compare/gson-parent-2.8.4...gson-parent-2.8.9)

---
updated-dependencies:
- dependency-name: com.google.code.gson:gson
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/pack-dependencies/pom.xml b/pack-dependencies/pom.xml
index f247357..080637c 100644
--- a/pack-dependencies/pom.xml
+++ b/pack-dependencies/pom.xml
@@ -67,7 +67,7 @@
 
     <!-- json -->
     <jackson.version>2.13.1</jackson.version>
-    <gson.version>2.8.4</gson.version>
+    <gson.version>2.8.9</gson.version>
 
     <disruptor.version>3.3.7</disruptor.version>
     <dubbo.version>2.6.12</dubbo.version>