semodule-utils: add RossComputerGuy as maintainer

pkgs/os-specific/linux/semodule-utils/default.nix

···
     description = "SELinux policy core utilities (packaging additions)";
     license = licenses.gpl2;
     inherit (libsepol.meta) homepage platforms;
-    maintainers = [ ];
+    maintainers = with maintainers; [ RossComputerGuy ];
   };
 }