Kotlin Gradle Plugin - clean caches for in-process compilation

This is to prevent file handle leaks on Windows. This
commit disposes KotlinCoreEnvironment used during
in-process compilation.

^KT-49772 Fixed

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinCoreEnvironment.kt

@@ -573,6 +573,7 @@ class KotlinCoreEnvironment private constructor(
         /**
          * This method is also used in Gradle after configuration phase finished.
          */
+        @JvmStatic
         fun disposeApplicationEnvironment() {
             synchronized(APPLICATION_LOCK) {
                 val environment = ourApplicationEnvironment ?: return