KAPT: Skip importing java.lang.System in the stubs

This fixes KT-43117

plugins/kapt3/kapt3-compiler/testData/converter/errorSuperclass.txt

@@ -1,7 +1,5 @@
 package test;
 
-import java.lang.System;
-
 @java.lang.annotation.Retention(value = java.lang.annotation.RetentionPolicy.RUNTIME)
 @kotlin.Metadata()
 public abstract @interface Anno {
@@ -11,8 +9,6 @@ public abstract @interface Anno {
 
 package test;
 
-import java.lang.System;
-
 @Anno()
 @kotlin.Metadata()
 @kotlin.Suppress(names = {"UNRESOLVED_REFERENCE"})