Use tmp_path fixture to avoid Bandit B108 being flagged

c.f. B108: hardcoded_tmp_directory

Flagged by Codecov

Author: matthewfeickert

tests/test_import.py

@@ -108,12 +108,12 @@ def test_process_normfactor_configs():
     assert result['ParallelMeasurement']['mu_both']['bounds'] == [[1.0, 5.0]]
 
 
-def test_process_channel_missing_root(mocker):
+def test_process_channel_missing_root(mocker, tmp_path):
     # mock missing ElementTree root
     mock_channelxml = mocker.Mock(spec=ET.ElementTree)
     mock_channelxml.getroot.return_value = None
 
-    resolver = pyhf.readxml.resolver_factory(Path("/tmp"), [])
+    resolver = pyhf.readxml.resolver_factory(tmp_path, [])
 
     with pytest.raises(RuntimeError, match="Root element of ElementTree is missing"):
         pyhf.readxml.process_channel(mock_channelxml, resolver)