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/HTML/HTMLFormElement.cpp

@@ -59,8 +59,7 @@ void HTMLFormElement::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
     visitor.visit(m_elements);
-    for (auto& element : m_associated_elements)
-        visitor.visit(element);
+    visitor.visit(m_associated_elements);
     visitor.visit(m_planned_navigation);
 }