build(deps): bump protobuf.version from 3.21.5 to 3.21.6 (#2800)

Bumps `protobuf.version` from 3.21.5 to 3.21.6.

Updates `protobuf-java` 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)

Updates `protobuf-java-util` from 3.21.5 to 3.21.6

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

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -166,7 +166,7 @@
         <wire-compiler.version>3.7.1</wire-compiler.version>
         <jimfs.version>1.1</jimfs.version>
         <icu4j.version>71.1</icu4j.version>
-        <protobuf.version>3.21.5</protobuf.version>
+        <protobuf.version>3.21.6</protobuf.version>
         <xmlsec.version>3.0.0</xmlsec.version>
         <protobuf.googleapi.types.version>2.9.2</protobuf.googleapi.types.version>
         <wsdl4j.version>1.6.3</wsdl4j.version>