Bump avro.version

Bumps `avro.version` from 1.12.0 to 1.12.1.

Updates `org.apache.avro:avro` from 1.12.0 to 1.12.1

Updates `org.apache.avro:avro-maven-plugin` from 1.12.0 to 1.12.1

---
updated-dependencies:
- dependency-name: org.apache.avro:avro
  dependency-version: 1.12.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.apache.avro:avro-maven-plugin
  dependency-version: 1.12.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

kafka-exercises-solutions/6.2-java-avro-clients/java-avro-producer/pom.xml

@@ -15,7 +15,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.compiler.source>17</maven.compiler.source>
         <maven.compiler.target>17</maven.compiler.target>
-        <avro.version>1.12.0</avro.version>
+        <avro.version>1.12.1</avro.version>
         <confluent.version>8.1.0</confluent.version>
     </properties>