Major updates to Java Modern.
This updates Kordamp to 0.25 from 0,19 to bring in new functionality and fix bugs. In particular on 0.19 Java Modern had bugs when being used in Gradle multi-project configurations due to issues in Kordamp. These are now resolved.
The signing plugin is now conditionally applied. It is not applied if there is no signing key provided. This makes building in dev environments easier.
Dependency management versions have been updated to their latest stable versions.
The SAP JDK tests now ues the latest Docker image instead of being fixed to JDK releases.