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/radio/hackrf/default.nix

@@ -32,6 +32,6 @@ stdenv.mkDerivation rec {
     homepage = "http://greatscottgadgets.com/hackrf/";
     license = licenses.gpl2;
     platforms = platforms.all;
-    maintainers = with maintainers; [ sjmackenzie the-kenny ];
+    maintainers = with maintainers; [ sjmackenzie ];
   };
 }