Fix type hints.

Author: domdfcoding

domdf_python_tools/dates.py

@@ -182,7 +182,7 @@ def utc_timestamp_to_datetime(
 if sys.version_info <= (3, 7, 2):
 	MonthsType = OrderedDict
 else:
-	MonthsType = typing.OrderedDict[str, str]
+	MonthsType = typing.OrderedDict[str, str]  # type: ignore
 
 #: Mapping of 3-character shortcodes to full month names.
 months: MonthsType = OrderedDict(