repl: Get pkgs instance before module systems

We build our nixpkgs instance ahead of time and pass it into nixos,
home-manager, system-manager and whatever else we can pass nixpkgs into.
So for the repl.pkgs we just take that pkgs instance and use it.

repl/flake-module.nix

@@ -12,7 +12,7 @@
       user = builtins.getEnv "USER";
     in
     rec {
-      pkgs = (self.nixosConfigurations.${host} or self.homeConfigurations."${user}@${host}").pkgs;
+      pkgs = withSystem builtins.currentSystem ({ pkgs, ... }: pkgs);
       fmt = inputs.treefmt-nix.lib.evalModule pkgs ../fmt/default.nix;
       lib = pkgs.lib;
       inherit self inputs;