Bump kafka-libs.version from 6.1.4 to 7.2.1

Bumps `kafka-libs.version` from 6.1.4 to 7.2.1.

Updates `kafka-avro-serializer` from 6.1.4 to 7.2.1
- [Release notes](https://github.com/confluentinc/schema-registry/releases)
- [Commits](confluentinc/schema-registry@v6.1.4...v7.2.1)

Updates `kafka-schema-registry-client` from 6.1.4 to 7.2.1
- [Release notes](https://github.com/confluentinc/schema-registry/releases)
- [Commits](confluentinc/schema-registry@v6.1.4...v7.2.1)

Updates `kafka-protobuf-serializer` from 6.1.4 to 7.2.1
- [Release notes](https://github.com/confluentinc/schema-registry/releases)
- [Commits](confluentinc/schema-registry@v6.1.4...v7.2.1)

---
updated-dependencies:
- dependency-name: io.confluent:kafka-avro-serializer
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: io.confluent:kafka-schema-registry-client
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: io.confluent:kafka-protobuf-serializer
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

pom.xml

@@ -22,7 +22,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <protobuf.version>3.19.1</protobuf.version>
         <testcontainers.version>1.17.3</testcontainers.version>
-        <kafka-libs.version>6.1.4</kafka-libs.version>
+        <kafka-libs.version>7.2.1</kafka-libs.version>
     </properties>
 
     <scm>