Replace Scala.js wit Scala Native

utest/native/PlatformShims.scala

@@ -12,7 +12,7 @@ object PlatformShims {
     f.value match {
       case Some(v) => v.get
       case None => throw new IllegalStateException(
-        "Test that returns Future must be run asynchronously in Scala.js, see TestTreeSeq::runAsync"
+        "Test that returns Future must be run asynchronously in Scala Native, see TestTreeSeq::runAsync"
       )
     }
   }