As part of removing JavaFX from the JDK the javapackager tool, and the jdk.packager and jdk.packager.services modules were necessarily removed as well.
The javapackager is not included with OpenJDK builds, nor will it be included with standalone JavaFX builds. Instead we are looking to provide a replacement tool in OpenJDK.
In the mean time, developers can use the existing javapackager tool from JDK 10.
I note that the sources will still be available, either in the 11-dev/rt repo or in the jfx-dev/rt repo by cloning (or updating) the repo from the 11+23 tag.