Tune unbound cached records a bit to answer faster

hosts/carbon/configuration.nix

@@ -435,6 +435,10 @@
       server = {
         interface = [ "fd00:152:152::1" "10.152.0.1" ];
         access-control = [ "::/0 allow" "0.0.0.0/0 allow" ];
+        prefer-ip6 = true;
+        prefetch = true;
+        serve-expired = true;
+        serve-expired-ttl-reset = true;
       };
     };
   };

hosts/palladium/backup-scripts.nix

@@ -40,5 +40,5 @@ let
   '';
 
 in {
-  environment.systemPackages = with pkgs; [ pkgs.cryptsetup pkgs.rsync cb-mount cb-sync cb-unmount ];
+  environment.systemPackages = with pkgs; [ pkgs.cryptsetup cb-mount cb-sync cb-unmount ];
 }