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/Streams/ReadableStreamBYOBReader.cpp

@@ -56,8 +56,7 @@ void ReadableStreamBYOBReader::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
     ReadableStreamGenericReaderMixin::visit_edges(visitor);
-    for (auto& request : m_read_into_requests)
-        visitor.visit(request);
+    visitor.visit(m_read_into_requests);
 }
 
 class BYOBReaderReadIntoRequest : public ReadIntoRequest {