Support Gradle's isolated projects feature

https://docs.gradle.org/current/userguide/isolated_projects.html

Experimenting with the feature today shows that our ResolvableDependencies, used both for layered jars and for identifying GraalVM metadata , isn't compatible. https://github.com/gradle/gradle/issues/31973 is tracking a change in Gradle will hopefully improve the situation.

Related, https://github.com/spring-gradle-plugins/dependency-management-plugin/issues/380 is tracking a similar enhancement to the dependency management plugin. In addition to being blocked on the above Gradle issue, it's also blocked on https://github.com/gradle/gradle/issues/25179.