mentioned event Add method crash fix in changelog

Author: lostmsu

CHANGELOG.md

@@ -22,6 +22,7 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 ### Fixed
 
 -   Fixed RecursionError for reverse operators on C# operable types from python. See #2240
+-   Fixed crash when .NET event has no `AddMethod`
 
 ## [3.0.3](https://github.com/pythonnet/pythonnet/releases/tag/v3.0.3) - 2023-10-11