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/games/flightgear/default.nix

@@ -73,7 +73,7 @@ stdenv.mkDerivation rec {
 
   meta = with stdenv.lib; {
     description = "Flight simulator";
-    maintainers = with maintainers; [ raskin the-kenny ];
+    maintainers = with maintainers; [ raskin ];
     platforms = platforms.linux;
     hydraPlatforms = []; # disabled from hydra because it's so big
     license = licenses.gpl2;