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/gqrx/default.nix

@@ -43,6 +43,6 @@ mkDerivation rec {
     # it's currently unknown which version of the BSD license that is.
     license = licenses.gpl3Plus;
     platforms = platforms.linux;  # should work on Darwin / macOS too
-    maintainers = with maintainers; [ bjornfor the-kenny fpletz ];
+    maintainers = with maintainers; [ bjornfor fpletz ];
   };
 }