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/Fetch/Infrastructure/HTTP/Headers.h

@@ -14,8 +14,8 @@
 #include <AK/String.h>
 #include <AK/Vector.h>
 #include <LibJS/Forward.h>
-#include <LibJS/Heap/Cell.h>
 #include <LibJS/Heap/GCPtr.h>
+#include <LibJS/Heap/Heap.h>
 #include <LibWeb/MimeSniff/MimeType.h>
 
 namespace Web::Fetch::Infrastructure {
@@ -35,6 +35,7 @@ class HeaderList final
     : public JS::Cell
     , Vector<Header> {
     JS_CELL(HeaderList, JS::Cell);
+    JS_DECLARE_ALLOCATOR(HeaderList);
 
 public:
     using Vector::begin;