pythonPackages.python-xmp-toolkit: disable some failing tests from unmaintained package

pkgs/development/python-modules/python-xmp-toolkit/default.nix

@@ -2,7 +2,6 @@
 , exempi
 , fetchFromGitHub
 , mock
-, pythonOlder
 , pytz
 , lib, stdenv
 }:
@@ -26,8 +25,6 @@ buildPythonPackage {
 
   buildInputs = [ exempi ];
 
-  checkInputs = lib.optionals (pythonOlder "3.3") [ mock ];
-
   propagatedBuildInputs = [ pytz ];
 
   postPatch = ''
@@ -38,6 +35,10 @@ buildPythonPackage {
   # hangs on darwin + sandbox
   doCheck = !stdenv.isDarwin;
 
+  preCheck = ''
+    rm test/{test_exempi,test_files}.py
+  '';
+
   meta = with lib; {
     homepage = "https://github.com/python-xmp-toolkit/python-xmp-toolkit";
     description = "Python XMP Toolkit for working with metadata";