Update dependency com.google.protobuf:protobuf-java to v4

Author: renovate[bot]

coursera-pcdp-parallel-concurrent-distributed-java/distributed-java/pom.xml

@@ -41,7 +41,7 @@
     </dependencies>
 
     <properties>
-        <protobuf.version>3.25.6</protobuf.version>
+        <protobuf.version>4.30.0</protobuf.version>
         <spark.version>3.5.5</spark.version>
 
     </properties>