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/stm32flash/default.nix

@@ -21,6 +21,6 @@ stdenv.mkDerivation rec {
     homepage = "https://sourceforge.net/projects/stm32flash/";
     license = stdenv.lib.licenses.gpl2;
     platforms = platforms.all; # Should work on all platforms
-    maintainers = with maintainers; [ the-kenny elitak ];
+    maintainers = with maintainers; [ elitak ];
   };
 }