Fix entries closing on saving compiled script to jar:

also adding a short sleep in tests, otherwise in some cases the
classloader was not able to find class in the jar.
Fixes script to jar saving tests on windows

libraries/scripting/jvm-host-test/test/kotlin/script/experimental/jvmhost/test/ScriptingHostTest.kt

@@ -112,6 +112,7 @@ class ScriptingHostTest : TestCase() {
         val compilationConfiguration = createJvmCompilationConfigurationFromTemplate<SimpleScriptTemplate>()
         val host = BasicJvmScriptingHost(evaluator = BasicJvmScriptJarGenerator(outJar))
         host.eval("println(\"$greeting\")".toScriptSource(name = "SavedScript.kts"), compilationConfiguration, null).throwOnFailure()
+        Thread.sleep(100)
         val classloader = URLClassLoader(arrayOf(outJar.toURI().toURL()), ScriptingHostTest::class.java.classLoader)
         val scriptClass = classloader.loadClass("SavedScript")
         val output = captureOut {
@@ -139,6 +140,8 @@ class ScriptingHostTest : TestCase() {
             saver(compiledScript, ScriptEvaluationConfiguration.Default).throwOnFailure()
         }
 
+        Thread.sleep(100)
+
         val classpathFromJar = run {
             val manifest = JarFile(outJar).manifest
             manifest.mainAttributes.getValue("Class-Path").split(" ") // TODO: quoted paths