[Feature Request] Add an programmatic API to share context between prerender workers during getStaticPaths and getStaticProps

[SukkaW]

Describe the feature you'd like to request

RT.

Context: #32981

In short, I am using a node library at local as my backend CMS. Unlike requesting a remote GraphQL endpoint or querying a database (which is damn slow), it is FAAAAASSSSST enough that I need just one instance. With the Next.js multi-thread feature when prerendering the static page, starting multiple instances of the library actually makes the build slower.

Related context

• The content of Next.js worker where every component is individual: https://github.com/vercel/next.js/blob/canary/packages/next/export/worker.ts
• Where Next.js starts multiple instances of the pretender worker:
  

  next.js/packages/next/build/index.ts

  Lines 780 to 791 in cfa8ab9

  	const timeout = config.staticPageGenerationTimeout || 0
  	const sharedPool = config.experimental.sharedPool || false
  	const staticWorker = sharedPool
  	? require.resolve('./worker')
  	: require.resolve('./utils')
  	let infoPrinted = false
  	process.env.NEXT_PHASE = PHASE_PRODUCTION_BUILD
  	const staticWorkers = new Worker(staticWorker, {
  	timeout: timeout * 1000,
  	onRestart: (method, [arg], attempts) => {

Describe the solution you'd like

Allow getStaticProps and getStaticPaths to have a shared context where I can put the local node library CMS in.

Describe alternatives you've considered

An option to disable the multi-thread feature completely.