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/applications/graphics/rawtherapee/default.nix

@@ -38,7 +38,7 @@ stdenv.mkDerivation rec {
     description = "RAW converter and digital photo processing software";
     homepage = "http://www.rawtherapee.com/";
     license = stdenv.lib.licenses.gpl3Plus;
-    maintainers = with stdenv.lib.maintainers; [ jcumming mahe the-kenny ];
+    maintainers = with stdenv.lib.maintainers; [ jcumming mahe ];
     platforms = with stdenv.lib.platforms; linux;
   };
 }