fix: get next config before requiring devserver (#15885)

* fix: get next config before requiring devserver

* lint

Co-authored-by: Lachlan Miller <lachlan.miller.1990@outlook.com>

Author: djsilcock

npm/react/plugins/next/index.js

@@ -1,9 +1,13 @@
-const { startDevServer } = require('@cypress/webpack-dev-server')
 const findNextWebpackConfig = require('./findNextWebpackConfig')
 
 module.exports = (on, config) => {
   on('dev-server:start', async (options) => {
-    return startDevServer({ options, webpackConfig: await findNextWebpackConfig(config) })
+    const webpackConfig = await findNextWebpackConfig(config)
+
+    // require('webpack') now points to nextjs bundled version
+    const { startDevServer } = require('@cypress/webpack-dev-server')
+
+    return startDevServer({ options, webpackConfig })
   })
 
   config.env.reactDevtools = true