Flush dataManager in KotlinJpsBuildTest

Original commit: 8c7053552b

jps/jps-plugin/test/org/jetbrains/kotlin/jps/build/KotlinJpsBuildTest.kt

@@ -650,6 +650,7 @@ public class KotlinJpsBuildTest : AbstractKotlinJpsBuildTestCase() {
             builder.build(scopeBuilder.build(), false)
         }
         finally {
+            descriptor.dataManager.flush(false)
             descriptor.release()
         }
     }