Gradle 8.1 allows building this project with Java 20.
Spring Boot needs to be updated as well to support Gradle 8.1. This
change updates Spring Boot to the latest available version 3.1.0.
1. This change introduces the current SWT builds that exist in Maven;
removing the need to locate and capture the JAR files.
2. The current SWT change is to capture the new Mac OS X aarch64 builds
("Apple Silicon").
3. The current version of SWT, however, requires Java 11.
4. Due to the complexity of the prior Gradle build, it was restructured.
