Add silentcodeg to MAINTAINERS (#19771)

* Add silentcodeg to MAINTAINERS

* add missing trailing g to chat nick

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

Author: 3 people

MAINTAINERS

@@ -46,3 +46,4 @@ Jimmy Praet <jimmy.praet@telenet.be> (@jpraet)
 Leon Hofmeister <dev.lh@web.de> (@delvh) 
 Gusted <williamzijl7@hotmail.com) (@Gusted)
 singuliere <singuliere@autistici.org> (@singuliere)
+silentcode <silentcode@senga.org> (@silentcodeg)