doc: change "Version 4 UUID" to "version 4 UUID"

Refs: https://www.rfc-editor.org/rfc/rfc4122.txt

PR-URL: https://github.com/nodejs/node/pull/39682


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>