Package is not compatible with NodeJS ESM

[timofei-iatsenko]

The package exporting types for ESM incorrectly https://arethetypeswrong.github.io/?p=threads%401.7.0

That causes problems on the ESM projects with Typescript:

TS7016: Could not find a declaration file for module threads.
/Users/timofei.Iatsenko/Projects/js-lingui/node_modules/threads/index.mjs
implicitly has an any type.
There are types at
/Users/timofei.Iatsenko/Projects/js-lingui/node_modules/threads/dist/index.d.ts
, but this result could not be resolved when respecting package.json exports. The threads library may need to update its package.json or typings.

Basically for every module type cjs / esm, there should be own version of typings

"./dist/index.cjs"
"./dist/index.d.cts"

"./dist/index.mjs"
"./dist/index.d.mts"

More explanation is provided here https://github.com/arethetypeswrong/arethetypeswrong.github.io/blob/main/docs/problems/FalseCJS.md#common-causes

Currently exports field does not provide typings for ESM at all:

{
    ".": {
      "require": "./dist/index.js",
      "types": "./dist/index.d.ts",
      "default": "./index.mjs"
    },
    "./observable": {
      "require": "./observable.js",
      "types": "./observable.d.ts",
      "default": "./observable.mjs"
    },
    "./register": {
      "require": "./register.js",
      "types": "./register.d.ts",
      "default": "./register.mjs"
    },
    "./worker": {
      "require": "./worker.js",
      "types": "./worker.d.ts",
      "default": "./worker.mjs"
    }
  }

Note that just using the same d.ts file for the mjs target will not fix issue correctly, because it will masquerade ESM behind the CJS (read the article i provided above)