fix pystack test

qt/python/mantidqt/mantidqt/dialogs/errorreports/test/test_run_pystack.py

@@ -5,6 +5,7 @@
 #   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
 # SPDX - License - Identifier: GPL - 3.0 +
 
+from pathlib import Path
 from tempfile import NamedTemporaryFile, TemporaryDirectory
 from time import sleep
 from unittest import TestCase
@@ -49,16 +50,16 @@ def test_get_most_recent_core_dump_file_gets_the_latest_file(self, mock_check_wo
             for name in file_names:
                 open(f"{tmp_dir}/{name}", "a").close()
                 sleep(0.1)
-            latest_file = _get_most_recent_core_dump_file(tmp_dir)
+            latest_file = _get_most_recent_core_dump_file(Path(tmp_dir))
             self.assertEqual(latest_file.name, file_names[-1])
 
     @patch(f"{MODULE_PATH}.CORE_DUMP_RECENCY_LIMIT", 0.5)
     def test_get_most_recent_core_dump_file_returns_none_if_there_are_no_new_files(self):
         with TemporaryDirectory() as tmp_dir:
             open(f"{tmp_dir}/test", "a").close()
             sleep(0.6)
-            self.assertIsNone(_get_most_recent_core_dump_file(tmp_dir))
+            self.assertIsNone(_get_most_recent_core_dump_file(Path(tmp_dir)))
 
     def test_get_most_recent_core_dump_file_returns_none_if_the_dir_is_empty(self):
         with TemporaryDirectory() as tmp_dir:
-            self.assertIsNone(_get_most_recent_core_dump_file(tmp_dir))
+            self.assertIsNone(_get_most_recent_core_dump_file(Path(tmp_dir)))