Refactor back to a more modular configuration

modules/nixos/cli/podman.nix

@@ -0,0 +1,25 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.nixosModules.cli.podman;
+in
+{
+  options.nixosModules.cli.podman.enable = mkEnableOption "Enable podman";
+
+  config = mkIf cfg.enable {
+    virtualisation = {
+      oci-containers.backend = "podman";
+
+      podman = {
+        enable = true;
+
+        autoPrune = {
+          enable = true;
+          dates = "weekly";
+        };
+      };
+    };
+  };
+}