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/CSS/CSSTransition.h

@@ -16,6 +16,7 @@ namespace Web::CSS {
 
 class CSSTransition : public Animations::Animation {
     WEB_PLATFORM_OBJECT(CSSTransition, Animations::Animation);
+    JS_DECLARE_ALLOCATOR(CSSTransition);
 
 public:
     static JS::NonnullGCPtr<CSSTransition> create(JS::Realm&, PropertyID, size_t transition_generation);