Enable caching of native image building and test tasks (#409)

Enable caching for the native image building task and improves the caching effectiveness of some of the test tasks in the project.

docs/docs.gradle.kts

@@ -32,5 +32,5 @@ dependencies {
 tasks.test {
   inputs.files(fileTree("modules").matching {
     include("**/pages/*.adoc")
-  })
+  }).withPropertyName("asciiDocFiles").withPathSensitivity(PathSensitivity.RELATIVE)
 }