LibWeb: Make ResizeObserver GC-allocated

Author: https://github.com/awesomekling
Commit: 0dc2c27fa3
Pull-request: https://github.com/SerenityOS/serenity/pull/14816
Reviewed-by: https://github.com/ADKaster
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibWeb/Forward.h

@@ -453,7 +453,6 @@ class IntersectionObserverWrapper;
 class LocationObject;
 class OptionConstructor;
 class RangePrototype;
-class ResizeObserverWrapper;
 class URLSearchParamsIteratorWrapper;
 class URLSearchParamsWrapper;
 class URLWrapper;