build(deps): Bump protobuf-java from 3.21.4 to 3.21.6

Bumps [protobuf-java](https://github.com/protocolbuffers/protobuf) from 3.21.4 to 3.21.6.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.21.4...v3.21.6)

---
updated-dependencies:
- dependency-name: com.google.protobuf:protobuf-java
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

integrations/pom.xml

@@ -721,7 +721,7 @@
       <dependency>
         <groupId>com.google.protobuf</groupId>
         <artifactId>protobuf-java</artifactId>
-        <version>3.21.4</version>
+        <version>3.21.6</version>
       </dependency>
       <dependency>
         <groupId>com.squareup.okio</groupId>