meta: update AUTHORS info for nstepien

PR-URL: #45692
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: nstepien

.mailmap

@@ -380,6 +380,8 @@ Netto Farah <nettofarah@gmail.com>
 Nicholas Kinsey <pyrotechnick@feistystudios.com>
 Nick Sia <nicholas.sia@vgw.co> <31839263+nicksia-vgw@users.noreply.github.com>
 Nick Soggin <nicksoggin@gmail.com> <iSkore@users.noreply.github.com>
+Nicolas Stepien <stepien.nicolas@gmail.com>
+Nicolas Stepien <stepien.nicolas@gmail.com> <567105+nstepien@users.noreply.github.com>
 Nigel Kibodeaux <nigelmail@gmail.com> <nigel@team.about.me>
 Nikola Glavina <glavina.nikola5@gmail.com> <nikola.glavina@student.um.si>
 Nikolai Vavilov <vvnicholas@gmail.com>

AUTHORS

@@ -735,7 +735,7 @@ Steven Vercruysse <stcruy@users.noreply.github.com>
 Aleksanteri Negru-Vode <aleksanteri.negru-vode@aalto.fi>
 Mathieu Darse <mattdarse@gmail.com>
 Connor Peet <connor@peet.io>
-Mayhem <stepien.nicolas@gmail.com>
+Nicolas Stepien <stepien.nicolas@gmail.com>
 Olov Lassus <olov.lassus@gmail.com>
 Phillip Lamplugh <phillip.lamplugh@gmail.com>
 Kohei TAKATA <kt.koheitakata@gmail.com>