Bump protobuf-java from 3.21.5 to 3.21.6

Bumps [protobuf-java](https://github.com/protocolbuffers/protobuf) from 3.21.5 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@v3.21.5...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>

Author: dependabot[bot]

pom.xml

@@ -45,7 +45,7 @@
     <snakeyaml.version>1.32</snakeyaml.version>
     <slf4j.version>2.0.0</slf4j.version>
     <caffeine.version>2.9.3</caffeine.version>
-    <protobuf.version>3.21.5</protobuf.version>
+    <protobuf.version>3.21.6</protobuf.version>
     <junit.version>4.13</junit.version>
     <bucket4j.version>7.6.0</bucket4j.version>
     <bouncycastle.version>1.71.1</bouncycastle.version>