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/tools/networking/fping/default.nix

@@ -13,7 +13,6 @@ stdenv.mkDerivation rec {
   meta = with stdenv.lib; {
     homepage = "http://fping.org/";
     description = "Send ICMP echo probes to network hosts";
-    maintainers = with maintainers; [ the-kenny ];
     license = licenses.bsd0;
     platforms = platforms.all;
   };