Revert "🚧 remove motd after installation"

@SM9CC see https://github.com/CachyOS/calamares-config/blob/master/etc/calamares/modules/shellprocess.conf#L48

This reverts commit 0883635a5c.

archiso/airootfs/usr/local/bin/removeun

@@ -71,10 +71,5 @@ _try_v3(){
 
 }
 
-_remove_misc(){
-    rm /etc/motd || true
-}
-
 _clean_packages
 _try_v3
-_remove_misc