Switch to use implementation config

- Now switching to use implementation configuration as it
  works better with aot tooling.
- Relates #470

spring-shell-samples/spring-shell-samples.gradle

@@ -21,10 +21,3 @@ graalvmNative {
 		version = "0.1.1"
 	}
 }
-
-// TODO: workaround until boot's aot plugin automatically extends
-//       from all super configurations like graalvm's plugin does.
-configurations {
-	aotCompileClasspath.extendsFrom management
-	aotRuntimeClasspath.extendsFrom management
-}