feat(zfs): declare ZFS module

hosts/andromache/default.nix

@@ -91,6 +91,7 @@ in
     enable = true;
     interfaces.eno1 = { inherit (wolInterfaces.eno1) macAddress; };
   };
+  zfs.enable = true;
 
   disko.devices = {
     disk.data = {

hosts/astyanax/default.nix

@@ -67,6 +67,7 @@ in
     };
   };
   taskwarrior.enable = true;
+  zfs.enable = true;
 
   secrets.nixSigningKey.enable = true;
   restic-backup.enable = true;