[hotfix] Update copyright year to 2024

Author: MartijnVisser

NOTICE

@@ -1,5 +1,5 @@
 Apache Flink Kafka Connector
-Copyright 2014-2023 The Apache Software Foundation
+Copyright 2014-2024 The Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).