nixos/atd: remove "batch" from setuid wrappers

"batch" is a shell script so invoking it via setuid wrapper never worked
anyway. (The kernel drops perms on executables with shebang.) A previous
nixpkgs commit made "batch" invoke the NixOS setuid "at" wrapper to gain
needed privileges.

Thanks to @yesbox for noticing.

Changed files
+3 -1
nixos
modules
services
scheduling
+3 -1
nixos/modules/services/scheduling/atd.nix
···
config = mkIf cfg.enable {
+
# Not wrapping "batch" because it's a shell script (kernel drops perms
+
# anyway) and it's patched to invoke the "at" setuid wrapper.
security.wrappers = builtins.listToAttrs (
map (program: { name = "${program}"; value = {
source = "${at}/bin/${program}";
···
group = "atd";
setuid = true;
setgid = true;
-
};}) [ "at" "atq" "atrm" "batch" ]);
+
};}) [ "at" "atq" "atrm" ]);
environment.systemPackages = [ at ];