LibWeb: Move passing of Web object prototypes out of constructors

Author: https://github.com/trflynn89
Commit: af75493883
Pull-request: https://github.com/SerenityOS/serenity/pull/16945
Reviewed-by: https://github.com/alimpfard

Userland/Libraries/LibWeb/DOM/DOMImplementation.h

@@ -30,6 +30,7 @@ public:
 private:
     explicit DOMImplementation(Document&);
 
+    virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
 
     Document& document() { return m_document; }