LibWeb/HTML: Port Window.fetch() to IDL

Author: https://github.com/linusg
Commit: 5cc6b1c4db
Pull-request: https://github.com/SerenityOS/serenity/pull/17752
Reviewed-by: https://github.com/awesomekling

Userland/Libraries/LibWeb/HTML/Window.h

@@ -60,6 +60,7 @@ public:
 
     using WindowOrWorkerGlobalScopeMixin::atob;
     using WindowOrWorkerGlobalScopeMixin::btoa;
+    using WindowOrWorkerGlobalScopeMixin::fetch;
 
     // ^DOM::EventTarget
     virtual bool dispatch_event(DOM::Event&) override;