fix: incorrectly mapped toggleDevTools in custom menu fiddle (#40703)

docs/fiddles/menus/customize-menus/main.js

@@ -102,7 +102,7 @@ const template = [
         })(),
         click: (item, focusedWindow) => {
           if (focusedWindow) {
-            focusedWindow.toggleDevTools()
+            focusedWindow.webContents.toggleDevTools()
           }
         }
       },