The ApacheDS project has removed it's own Kerberos implementation, however there is a second Apache project Apache Kerby which is still actively maintained.

https://directory.apache.org/kerby/news.html

The last release of the Apache DS Kerberos libraries now have vulnerabilities reported against them but as they are no longer part of the project we know there will be no future releases with the fixes so we should migrate.

For LDAP testing however we will still need to use ApacheDS, this is just for the Kerberos KDC we need to migrate.