doc: move Sam Ruby to emeritus

Sam confirmed in email that they are not opposed to moving to emeritus
at this time.

PR-URL: https://github.com/nodejs/node/pull/39264


Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Sam Ruby <rubys@intertwingly.net>