@actions/artifact: convert to an ESM module (#2266)

* `@actions/artifact`: convert to an ESM module

* Update the package-lock.json

* Undo the GHES ignores

* Fix the reference to `@actions/http-client` in the lock file

* Bump `@actions/core` to `3.0.0`

* Remove `jest.config.cjs`

* Import `OctoKitOptions` from `@octokit/core/types`

* Pull the package version from `package.json`

* Workaround getting the package version for the user-agent

* Fix the `archiver` import

* Fix linting

packages/artifact/__tests__/retention.test.ts

@@ -1,5 +1,5 @@
-import {Timestamp} from '../src/generated'
-import * as retention from '../src/internal/upload/retention'
+import {Timestamp} from '../src/generated/index.js'
+import * as retention from '../src/internal/upload/retention.js'
 
 describe('retention', () => {
   beforeEach(() => {