doc: add VoltrexMaster to collaborators

Fixes: https://github.com/nodejs/node/issues/40323

PR-URL: https://github.com/nodejs/node/pull/40566


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>