Update tests/test_sort.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: bosd

tests/test_sort.py

@@ -77,7 +77,7 @@ def test_returns_none_if_columns_missing() -> None:
     file_path.unlink()
 
 
-def test_returns_none_for_non_existent_file() -> None:
+def test_returns_false_for_non_existent_file() -> None:
     """Verify that False is returned if the input file does not exist."""
     assert (
         sort_for_self_referencing(