docs: fix missing dependencies in ipc patterns (#33082)

docs/fiddles/ipc/pattern-2/main.js

@@ -1,4 +1,4 @@
-const {app, BrowserWindow, ipcMain,dialog} = require('electron')
+const {app, BrowserWindow, ipcMain, dialog} = require('electron')
 const path = require('path')
 
 async function handleFileOpen() {

docs/fiddles/ipc/pattern-3/main.js

@@ -1,4 +1,4 @@
-const {app, BrowserWindow, Menu} = require('electron')
+const {app, BrowserWindow, Menu, ipcMain} = require('electron')
 const path = require('path')
 
 function createWindow () {