Drop tasks inheritance from 'AbstractCompile' and 'SourceTask'

'AbstractCompile' task has inputs that are related only to Java
compilation and should not used for Kotlin compile tasks.

'SourceTask' most probably will be deprecated in future Gradle releases
- https://github.com/gradle/gradle/issues/9040. Plus it has
old 'sources' with 'FileTree' type which is not stable
for task inputs snapshotting.

Another breaking change - 'destinationDir' task property is not longer
available. It is replaced by 'destinationDirectory' which uses Gradle
Provider API type.

^KT-32805 In Progress

jps/jps-plugin/build.gradle.kts

@@ -106,8 +106,6 @@ tasks.compileJava {
 
 tasks.compileKotlin {
     kotlinOptions.jvmTarget = "1.8"
-    sourceCompatibility = "1.8"
-    targetCompatibility = "1.8"
 }
 
 projectTest(parallel = true) {