fix(nextjs): use require("next") since exports.default is no longer p…

…rovided (#16497)

(cherry picked from commit 786323d)

packages/next/src/executors/server/lib/default-server.ts

@@ -1,6 +1,4 @@
 import * as express from 'express';
-import * as path from 'path';
-import next from 'next';
 import { NextServerOptions, ProxyConfig } from '../../../utils/types';
 
 /**
@@ -11,6 +9,7 @@ export async function defaultServer(
   settings: NextServerOptions,
   proxyConfig?: ProxyConfig
 ): Promise<void> {
+  const next = require('next');
   const app = next(settings);
   const handle = app.getRequestHandler();