Merge pull request #2387 from Textualize/type-alias

dependency fix

Author: willmcgugan

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [12.5.1] - 2022-07-01
+
+### Fixed
+
+- Fixed missing typing extensions dependency on 3.9
+
 ## [12.5.0] - 2022-07-11
 
 ### Added