meta: consolidate AUTHORS entries for brettkiefer

PR-URL: #40599
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>

.mailmap

@@ -70,6 +70,7 @@ Brandon Benvie <brandon@bbenvie.com> <brandon@brandonbenvie.com>
 Brandon Kobel <kobelb@gmail.com> <brandon.kobel@elastic.co>
 Brendan Ashworth <brendan.ashworth@me.com> <squirrelslikeacorns@gmail.com>
 Brent Pendergraft <bpent3l@gmail.com>
+Brett Kiefer <kiefer@gmail.com> <brett@trello.com>
 Brian White <mscdex@mscdex.net>
 Brian White <mscdex@mscdex.net> <mscdex@gmail.com>
 Caleb Boyd <caleb.boyd@gmail.com>

AUTHORS

@@ -2218,7 +2218,6 @@ Misty De Meo <mistydemeo@gmail.com>
 James Kylstra <kylstraj@oregonstate.edu>
 Shelley Vohr <shelley.vohr@gmail.com>
 Deepjyoti Mondal <djmdeveloper060796@gmail.com>
-Brett Kiefer <brett@trello.com>
 Kevin Thomas <kevintab95@gmail.com>
 ZaneHannanAU <ZaneHannanAU@users.noreply.github.com>
 Fernando Doglio <deleteman@gmail.com>