iwd: drop systemd dep, not needed when specifying config flags too

Only used to guess if systemd-y bits should be installed,
which we manually specify already.  So drop unneeded dep.

pkgs/os-specific/linux/iwd/default.nix

@@ -8,7 +8,6 @@
 , docutils
 , readline
 , python3Packages
-, systemd
 }:
 
 stdenv.mkDerivation rec {
@@ -32,7 +31,6 @@ stdenv.mkDerivation rec {
     ell
     python3Packages.python
     readline
-    systemd
   ];
 
   pythonPath = [