Upgrade documentation site Vercel instance to use node 16

[ChristianMurphy]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)

Problem

Currently several dependencies are locked in place due to Vercel/Lambda previously only supporting up to Node.js 14

mdx/renovate.json5

Lines 13 to 15 in f4d78be

	// `node-loader@2` depends on Node 16+. Our website is on Vercel/AWS which don’t support Node 16.
	'@node-loader/babel',
	'@node-loader/core'

However now Node.js 16 is available, and those could be unlocked https://vercel.com/changelog/node-js-16-lts-is-now-available

Solution

A maintainer with access to the Vercel site changing the setting for Node.js version

Alternatives

Leaving the dependencies and the site locked at Node 14

[wooorm]

Site currently doesn’t build on v16 because the alpha react server components build needs Node v14 loaders.
And the RSC version that was shipped in React 18 is different from the one this site is built on

[wooorm]

This is now done!