fixup(checks/inventory): remove 'self' from clan settings; doesn't work in the nixos tests yet.

We need to reasearch why that is the case.
Removing the option for now to prevent weird bugs

checks/dummy-inventory-test/default.nix

@@ -7,10 +7,8 @@
     # - clan.service modules
     name = "dummy-inventory-test";
 
-    clanSettings = {
-      self = ./.;
-    };
     clan = {
+      directory = ./.;
       inventory = {
         machines.peer1 = { };
         machines.admin1 = { };