treewide: remove the-kenny from maintainers

@the-kenny did a good job in the past and is set as maintainer in many package,
however since 2017-2018 he stopped contributing. To create less confusion
in pull requests when people try to request his feedback, I removed him as
maintainer from all packages.

pkgs/os-specific/linux/usermount/default.nix

@@ -24,6 +24,5 @@ stdenv.mkDerivation {
     description = "A simple tool to automatically mount removable drives using UDisks2 and D-Bus";
     license = stdenv.lib.licenses.mit;
     platforms = stdenv.lib.platforms.linux;
-    maintainers = with stdenv.lib.maintainers; [ the-kenny ];
   };
 }