LibWeb: Add calls to JS_{DECLARE,DEFINE}_ALLOCATOR()

Author: https://github.com/mattco98
Commit: 31341b280a
Pull-request: https://github.com/SerenityOS/serenity/pull/23878
Issue: https://github.com/SerenityOS/serenity/issues/23805
Reviewed-by: https://github.com/awesomekling

Userland/Libraries/LibWeb/Layout/VideoBox.h

@@ -16,6 +16,7 @@ class VideoBox final
     : public ReplacedBox
     , public DOM::Document::ViewportClient {
     JS_CELL(VideoBox, ReplacedBox);
+    JS_DECLARE_ALLOCATOR(VideoBox);
 
 public:
     virtual void prepare_for_replaced_layout() override;