Test if type=module is allowed for v2 addons

[NullVoxPopuli]

Noticed an issue with a development ember build and got this error with type=module in the package.json of the v2 addon:

Build Error (PackagerRunner) in ../node_modules/.pnpm/file+ember-primitives_@glimmer+component@1.1.2_@glimmer+tracking@1.1.2_@glint+template@1.0.2__5flicjnelbvasblmzhqljcm6ai/node_modules/ember-primitives/dist/index.js

Module not found: Error: Can't resolve '<repo>/node_modules/.pnpm/@embroider+macros@1.11.0_@glint+template@1.0.2/node_modules/@embroider/macros/src/addon/es-compat' in '$TMPDIR/embroider/2194b3/node_modules/.pnpm/file+ember-primitives_@glimmer+component@1.1.2_@glimmer+tracking@1.1.2_@glint+template@1.0.2__5flicjnelbvasblmzhqljcm6ai/node_modules/ember-primitives/dist/index.js'
Did you mean 'es-compat.js'?
BREAKING CHANGE: The request '<repo>/node_modules/.pnpm/@embroider+macros@1.11.0_@glint+template@1.0.2/node_modules/@embroider/macros/src/addon/es-compat' failed to resolve only because it was resolved as fully specified
(probably because the origin is strict EcmaScript Module, e. g. a module with javascript mimetype, a '*.mjs' file, or a '*.js' file where the package.json contains '"type": "module"').
The extension in the request is mandatory for it to be fully specified.
Add the extension to the request.


Stack Trace and Error Report: /tmp/error.dump.65d732fa1322ef93e4dcf03a11d342ce.log

According to https://webpack.js.org/api/module-methods/
extensions are required.

What's the rest of the ecosystem doing? does Vite require extensions?
does the problem (requiring a .js extension) affect non-ember-addons using type=module? (TODO)
I would think that this shouldn't matter, due to the exports map not specifying extensions, and also disambiguating between import/require, etc.

Here is someone saying the bug is not in webpack: pmndrs/react-spring#2097 (comment)
but that issues was due to dist not being published 😅

[NullVoxPopuli]

Closing in favor of https://github.com/embroider-build/embroider/pull/1572/files