Update new_repo_checklist.md
Update new_repo_checklist.md

Updating required steps for non-sim repos. Removing blurb about the Machine User collaborator (_NOTE: If the repo is private, it is REQUIRED to add the Machine User collaborator (so automated processes can clone/pull the repo).)
phetsims/phet-info,phetsims/phet-info,phetsims/phet-info,phetsims/phet-info