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/development/tools/misc/teensy-loader-cli/default.nix

@@ -26,7 +26,6 @@ stdenv.mkDerivation rec {
     description = "Firmware uploader for the Teensy microcontroller boards";
     homepage = "https://www.pjrc.com/teensy/";
     license = licenses.gpl3;
-    maintainers = with maintainers; [ the-kenny ];
     platforms = platforms.unix;
   };
 }