Do not blank opt in for allowing kotlin package in all subprojects

-Xallow-kotlin-package must be specified explicitly to prevent
unintended declarations in kotlin package.

libraries/scripting/jsr223-test/build.gradle.kts

@@ -27,6 +27,10 @@ sourceSets {
     "test" { projectDefault() }
 }
 
+tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>> {
+    kotlinOptions.freeCompilerArgs += "-Xallow-kotlin-package"
+}
+
 projectTest(parallel = true)
 
 projectTest(taskName = "embeddableTest", parallel = true) {