Fix the csv file name test on case-insensitive file systems

On macOS and Windows, `out.CSV` and `out.csv` are the same file, so
the directory listing had one file, not two. Remove the listing check.
The check of the returned file name still finds the `out.csv.csv` bug.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: TalLevAmi

test/test_utils.py

@@ -202,8 +202,6 @@ def test_write_json_list_to_csv_file_name(self):
                 self.assertEqual(os.path.join(tmp_dir, expected), filename)
                 self.assertTrue(os.path.isfile(filename))
 
-            self.assertEqual(["out.CSV", "out.csv"], sorted(os.listdir(tmp_dir)))
-
     def test_whitelist_keys(self):
         """ should whitelist keys correctly """
         self.assertEqual([{"k1": "v1"}], whitelist_keys([{"k1": "v1", "k2": "v2"}], ["k1"]))