fix: minor fixes related to release (#5732)

* fix: use * for test plugin engines

This removes the need to update this version with every version change.

* refactor: use npm-package in release assets

This adds a new job to `release.yaml` to upload the `npm-package` to the
release assets which will also allow us to download it in the
`publish.yaml` workflow.

* docs: update release instructions

* fixup!: use package.tar.gz