feat: switch to ESM-only and import attributes

[43081j]

This switches to ESM only, which means:

• We drop tshy and just use TypeScript directly
• Use import attributes (i.e. import the JSON directly using import)

This does mean we require a newer Node, one that can require(esm) and
use import attributes (specifically JSON).

🔗 Linked issue

📚 Description

[43081j]

@bluwy this does mean our ESLint plugin will also require Node 20.

so if we wanted to keep 18.x support, i think we'd need one of the following:

• tell people to read the JSON file manually (as we would still ship it in the package)
• have a second entrypoint that uses readFile like we used to

thoughts?

[joaopedrodcf]

What do you think of us also adding to the package json the node version minimum for the package ?

[43081j]

i think we should but maybe lets do it in a follow up once we agree on the right one

[bluwy]

@bluwy this does mean our ESLint plugin will also require Node 20.

so if we wanted to keep 18.x support, i think we'd need one of the following:

• tell people to read the JSON file manually (as we would still ship it in the package)
• have a second entrypoint that uses readFile like we used to

thoughts?

I think telling to read the JSON file manually should be ok. There's still createRequire to require the json which shouldn't make it that hard.

[43081j]

that works for me 👍

we can add it to the export map too