Extract members from Kotlin tasks, don't iterate over them (KT-31713)

Refactor: move some properties from the Kotlin tasks to the
new task data model, so they can be accessed without forcing the
tasks to instantiate.

Don't iterate over Kotlin tasks of all projects in the IC-related code;
instead, inspect the model.

Issue #KT-31713 Fixed

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/GradleVersionRequired.kt

@@ -21,7 +21,7 @@ import org.junit.Assume
 
 sealed class GradleVersionRequired(val minVersion: String, val maxVersion: String?) {
     companion object {
-        const val OLDEST_SUPPORTED = "4.1"
+        const val OLDEST_SUPPORTED = "4.3"
     }
 
     class Exact(version: String) : GradleVersionRequired(version, version)