LibJS+LibWeb: Use new Cell::Visitor helpers to avoid manual iteration

Author: https://github.com/awesomekling
Commit: 53d0dd4a2e
Pull-request: https://github.com/SerenityOS/serenity/pull/23971
Reviewed-by: https://github.com/trflynn89

Userland/Libraries/LibWeb/CSS/CSSKeyframesRule.cpp

@@ -20,8 +20,7 @@ JS::NonnullGCPtr<CSSKeyframesRule> CSSKeyframesRule::create(JS::Realm& realm, Fl
 void CSSKeyframesRule::visit_edges(Visitor& visitor)
 {
     Base::visit_edges(visitor);
-    for (auto& keyframe : m_keyframes)
-        visitor.visit(keyframe);
+    visitor.visit(m_keyframes);
 }
 
 void CSSKeyframesRule::initialize(JS::Realm& realm)