python3Packages.css-parser: enable tests

pkgs/development/python-modules/css-parser/default.nix

@@ -2,6 +2,7 @@
   lib,
   buildPythonPackage,
   fetchPypi,
+  pytestCheckHook,
 }:
 
 buildPythonPackage rec {
@@ -14,9 +15,7 @@ buildPythonPackage rec {
     hash = "sha256-vx6XKtMzROkyBpZPtM2QjZ3e+fzQwB+pPg1zRnU5Q2M=";
   };
 
-  # Test suite not included in tarball yet
-  # See https://github.com/ebook-utils/css-parser/pull/2
-  doCheck = false;
+  nativeCheckInputs = [ pytestCheckHook ];
 
   pythonImportsCheck = [ "css_parser" ];