The jpackage tool moved from the jdk.incubator.jpackage module to jdk.jpackage in JDK 16. The `jdk.json` config file needs to be updated accordingly so that jpackage reviews are sent to core-libs-dev. Phil had to add it manually for:
https://github.com/openjdk/jdk/pull/2320
https://github.com/openjdk/jdk/pull/2320