Related to the comment here:
We currently only support Cassandra 3.x. Cassandra 3.x only supports Java 8 which means the Cassandra Connector can only be build with Java 8. We should upgrade to Cassandra 4.x dependencies and support of Cassandra 4+ in order to get Java >= 9 support.
This will also contribute to
DBZ-2513 "Add Java Outreach to incubator repository"