Enable the test

Author: jaraco

setuptools/tests/test_sdist.py

@@ -823,7 +823,6 @@ def get_source_files(self):
         manifest = cmd.filelist.files
         assert '.myfile~' in manifest
 
-    @pytest.mark.xfail(reason="4615")
     def test_build_base_pathlib(self, source_dir):
         """
         Ensure if build_base is a pathlib.Path, the build still succeeds.