message: Add test for None description
diff: @@ -4,3 +4,6 @@ class TestCursorDescription(object):
  def test_description(self, duckdb_cursor):
  description = duckdb_cursor.execute("SELECT * FROM integers").description
  assert description == [('i', None, None, None, None, None, None)]
  +
  + def test_none_description(self, duckdb_cursor):
  + assert duckdb_cursor.description is None
  