Port PR 61805 - module=node20

[jakebailey]

Ports microsoft/TypeScript#61805

[Copilot]

Pull Request Overview

This PR ports TypeScript PR 61805 to address changes related to the module=node20 configuration, focusing on updates to module resolution behavior and module format handling in Node.js 20 environments.

Key changes include:

• Removal of legacy module resolution validation errors
• Updated module output formats for ESM vs CJS contexts
• Improved import assertion to import attributes error messaging
• Corrected module resolution strategy selection

Reviewed Changes

Copilot reviewed 300 out of 645 changed files in this pull request and generated no comments.

File	Description
Multiple baseline error files	Removed TS5109 errors requiring Node16 module resolution with Node20 module setting
Multiple baseline JavaScript output files	Updated module compilation output to use proper ESM syntax instead of CommonJS when appropriate
Import assertion baseline files	Changed error messages from import assertions to import attributes deprecation warnings
Module resolution trace files	Updated to show Node16 resolution strategy instead of Bundler

[jakebailey]

Hm, data race...

[jakebailey]

I can't figure out how to deal with the circularity errors when compiling concurrently. These are the kinds of errors that we have been silencing by skipping the tests (concurrentSkippedErrorBaselines), which would defeat the purpose of these checks. I am not sure if this means the tests are "bad" themselves for introducing those circularities, or if there's a bug in my (or someone else's) ported code that's causing the issue.

[jakebailey]

The symbol baselines doing something like:

Implies that we are somehow choosing the wrong import when compiling concurrently, so I hope it's just that kind of bug, but the race detector does not detect anything.