checks/update: convert to inventory test

checks/update/default.nix

@@ -0,0 +1,49 @@
+{
+  pkgs,
+  self,
+  clanLib,
+  ...
+}:
+clanLib.test.makeTestClan {
+  inherit pkgs self;
+  nixosTest = (
+    { lib, ... }:
+    let
+      machines = [
+        "machine"
+      ];
+    in
+    {
+      name = "update";
+
+      clan = {
+        directory = ./.;
+        inventory = {
+          machines = lib.genAttrs machines (_: { });
+        };
+      };
+
+      defaults =
+        { ... }:
+        {
+          environment.systemPackages = [ self.packages.${pkgs.hostPlatform.system}.clan-cli-full ];
+          services.openssh.enable = true;
+        };
+
+      nodes = {
+        machine-updated = {
+          environment.etc."testfile".text = "updated";
+        };
+      };
+
+      testScript = ''
+        start_all()
+        machine.wait_for_open_port(22)
+
+        machine.fail("cat /etc/testfile")
+        machine.succeed("env CLAN_DIR=${self} clan machines update test-update-machine-${pkgs.hostPlatform.system} --debug")
+        assert machine.succeed("cat /etc/testfile") == "updated"
+      '';
+    }
+  );
+}