add python 3.11 support to CHANGES

Author: joshuadavidthomas

CHANGES.rst

@@ -11,6 +11,7 @@ Unreleased
 - Added support for Django 4.1 (gh-1021)
 - Added ``tracked_fields`` attribute to historical models (gh-1038)
 - Fixed ``KeyError`` when running ``clean_duplicate_history`` on models with ``excluded_fields`` (gh-1038)
+- Added support for Python 3.11 (gh-1053)
 
 3.1.1 (2022-04-23)
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