replace window_to_front with `window.to_front (#5154)

Author: ndonkoHenri

sdk/python/packages/flet/src/flet/core/page.py

@@ -1071,7 +1071,7 @@ async def __on_authorize_async(self, e) -> None:
                 self.close_in_app_web_view()
             else:
                 # activate desktop window
-                self.window_to_front()
+                self.window.to_front()
         login_evt = LoginEvent(
             error=d.get("error"),
             error_description=d.get("error_description"),