host/shared: use unstable docker package

nixos/hosts/magenta/default.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, lib, ... }:
+{ pkgs, ... }:
 
 let
   data = import ../../../data.nix;

nixos/shared/docker-swarm.nix

@@ -1,10 +1,11 @@
-{ ... }:
+{ pkgs, ... }:
 
 {
   # Enable docker
   virtualisation.docker = {
     enable = true;
     liveRestore = false;
+    package = pkgs.unstable.docker;
   };
   # Source: https://forums.docker.com/t/error-response-from-daemon-rpc-error-code-unavailable-desc-grpc-the-connection-is-unavailable/39066/12
   networking.firewall = {