systemd: explicitly disable homed for now

We don't currently have tests to ensure it works and keeps working.

So instead of having it accidentially working, and possibly breaking it
in the future, disable it for now.

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

@@ -109,6 +109,7 @@ in stdenv.mkDerivation {
     "-Dtests=false"
     "-Dimportd=true"
     "-Dlz4=true"
+    "-Dhomed=false"
     "-Dhostnamed=true"
     "-Dnetworkd=true"
     "-Dsysusers=false"