pyproject: update bleak to v0.20.0

v1.19.5 is broken for many windows users.

Author: dlech

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Updated `bleak` dependency to v0.20.0.
+
 ## [1.0.0-alpha.39] - 2023-03-06
 
 ### Fixed