LibWeb: Make DOMTokenList GC-allocated

Author: https://github.com/awesomekling
Commit: 0176d42f49
Pull-request: https://github.com/SerenityOS/serenity/pull/14816
Reviewed-by: https://github.com/ADKaster
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibWeb/DOM/DOMTokenList.idl

@@ -1,3 +1,4 @@
+[NoInstanceWrapper]
 interface DOMTokenList {
     readonly attribute unsigned long length;
     getter DOMString? item(unsigned long index);