ruby: remove myself as maintainer/CODEOWNER

It's been at least a year since I kept up to date with Ruby, and I
don't think I really have anything left to offer Nixpkgs in terms of
Ruby expertise.

pkgs/development/ruby-modules/bundix/default.nix

@@ -47,7 +47,7 @@ buildRubyGem rec {
     '';
     homepage = "https://github.com/manveru/bundix";
     license = "MIT";
-    maintainers = with lib.maintainers; [ manveru qyliss zimbatm ];
+    maintainers = with lib.maintainers; [ manveru zimbatm ];
     platforms = lib.platforms.all;
   };
 }