LibWeb: Fire resize event at the Window instead of Document

The spec says "fire an event named resize at the Window object
associated with doc."

However, we were accidentally firing it at `doc` instead of the Window.

Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -1286,7 +1286,7 @@ void Document::run_the_resize_steps()
         return;
     m_last_viewport_size = viewport_size;
 
-    dispatch_event(DOM::Event::create(UIEvents::EventNames::resize));
+    window().dispatch_event(DOM::Event::create(UIEvents::EventNames::resize));
 
     update_layout();
 }