python3Packages.treelib: use pyproject, unbreak (#439894)

pkgs/development/python-modules/treelib/default.nix

@@ -2,6 +2,7 @@
   lib,
   buildPythonPackage,
   fetchFromGitHub,
+  poetry-core,
   six,
   pytestCheckHook,
 }:
@@ -9,7 +10,7 @@
 buildPythonPackage rec {
   pname = "treelib";
   version = "1.8.0";
-  format = "setuptools";
+  pyproject = true;
 
   src = fetchFromGitHub {
     owner = "caesar0301";
@@ -18,7 +19,9 @@ buildPythonPackage rec {
     hash = "sha256-jvaZVy+FUcCcIdvWK6zFL8IBVH+hMiPMmv5shFXLo0k=";
   };
 
-  propagatedBuildInputs = [ six ];
+  build-system = [ poetry-core ];
+
+  dependencies = [ six ];
 
   nativeCheckInputs = [ pytestCheckHook ];