python313Packages.webob: fix build

The cgi module was removed in Python 3.13 but can be brought back using
the legacy-cgi package.

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

@@ -2,14 +2,17 @@
   lib,
   buildPythonPackage,
   fetchPypi,
+  setuptools,
+  legacy-cgi,
   pytestCheckHook,
+  pythonAtLeast,
   pythonOlder,
 }:
 
 buildPythonPackage rec {
   pname = "webob";
   version = "1.8.7";
-  format = "setuptools";
+  pyproject = true;
 
   disabled = pythonOlder "3.7";
 
@@ -19,6 +22,11 @@ buildPythonPackage rec {
     hash = "sha256-tk71FBvlWc+t5EjwRPpFwiYDUe3Lao72t+AMfc7wwyM=";
   };
 
+  build-system = [ setuptools ];
+
+  # https://github.com/Pylons/webob/issues/437
+  dependencies = lib.optionals (pythonAtLeast "3.13") [ legacy-cgi ];
+
   nativeCheckInputs = [ pytestCheckHook ];
 
   pythonImportsCheck = [ "webob" ];