py3: Remove "from six.moves import range".

This is no longer required, since in Python 3, this is what the range
built-in does.

tools/lib/template_parser.py

@@ -1,5 +1,4 @@
 from typing import Callable, List, Optional
-from six.moves import range
 
 class TemplateParserException(Exception):
     def __init__(self, message):