doc: move ofrobots to collaborator emeritus

Ali indicated in email that it makes sense to move him to collaborator
emeritus at this time.

PR-URL: https://github.com/nodejs/node/pull/39307


Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>