docs(CHANGES): Note Deprecation warning fix

Author: tony

CHANGES

@@ -14,6 +14,10 @@ $ pip install --user --upgrade --pre libtmux
 
 <!-- Maintainers and contributors: Insert change notes for the next release above -->
 
+#### Bug fixes
+
+- Use {exc}`DeprecationWarning` for APIs set to be deprecated (#526)
+
 ## libtmux 0.28.1 (2024-02-15)
 
 _Maintenance only, no bug fixes or new features_