refactor(ci): fix npm workflows (#4797)

* feat: refactor npm workflows to use download-artifact

This refactors the npm workflows to use the download-artifact GitHub Action. We
had problems in the past with our download_artifact custom bash function. This
also fixes an issue where we weren't downloading the correct artifacts when
publishing beta and dev tags to npm.

* fixup: remove unused env var

* fixup! add download-artifcat to npm-brew"

* fixup! remove unnecessary code comment

* fixup! move NPM_ENVIRONMENT logic to script