Removed hard-coded ensure_clean

Author: WillAyd

pandas/tests/io/test_excel.py

@@ -1374,7 +1374,9 @@ def test_to_excel_interval_labels(self, merge_cells, engine, ext):
 
     def test_to_excel_timedelta(self, merge_cells, engine, ext):
         # GH 19242, GH9155 - test writing timedelta to xls
-        with ensure_clean('.xls') as path:
+        if engine == 'openpyxl':
+            pytest.skip('Timedelta roundtrip broken with openpyxl')
+        with ensure_clean(ext) as path:
             frame = DataFrame(np.random.randint(-10, 10, size=(20, 1)),
                               columns=['A'],
                               dtype=np.int64