Add --module node20 with require(esm) support

[andrewbranch]

Fixes #60534

require(esm) is currently unflagged in Node.js v22, but may be in v20 by the time this PR lands for 5.8. We’ll have a discussion about the flag name if it doesn’t happen by 5.8-beta.

This PR does not currently attempt to error on require calls of async modules (those with top-level await). We do not emit any special marker in declaration files indicating the presence of TLA, which is a prerequisite. My suspicion is that the sentiment will be that a static check for async modules in the require graph is not worth the pain of making a backward-incompatible declaration file change.

The other change in this PR is that import assertions are now prohibited in --module nodenext, since Node.js v22+ does not parse them. Since there have been a lot of module target changes in fast succession, here’s the summary:

5.6

	target	moduleResolution	import assertions	import attributes	JSON imports	require(esm)
node16	es2022	node16	❌	❌	no restrictions	❌
nodenext	esnext	nodenext	✅	✅	no restrictions	❌

5.7.3

	target	moduleResolution	import assertions	import attributes	JSON imports	require(esm)
node16	es2022	node16	❌	❌	no restrictions	❌
nodenext	esnext	nodenext	✅	✅	needs type "json"	❌

5.8

	target	moduleResolution	import assertions	import attributes	JSON imports	require(esm)
node16	es2022	node16	❌	❌	no restrictions	❌
node18	es2022	node16	✅	✅	needs type "json"	❌
node20	es2023	node16	✅	✅	needs type "json"	✅
nodenext	esnext	nodenext	❌	✅	needs type "json"	✅

[typescript-bot]

Thanks for the PR! It looks like you've changed the TSServer protocol in some way. Please ensure that any changes here don't break consumers of the current TSServer API. For some extra review, we'll ping @sheetalkamat, @mjbvz, @zkat, and @joj for you. Feel free to loop in other consumers/maintainers if necessary.

[typescript-bot]

Looks like you're introducing a change to the public API surface area. If this includes breaking changes, please document them on our wiki's API Breaking Changes page.

Also, please make sure @DanielRosenwasser and @RyanCavanaugh are aware of the changes, just as a heads up.

[marco-ippolito]

I will probably release Node v20 with the backport for require(esm) around half of January 🙂