Update CHANGELOG.md

Author: cptartur

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 #### Changed
 
 - Minimal supported `Scarb` version is now `2.10.0` (updated from `2.9.1`)
+- Minimal supported `snforge_std` and `snforge_std_deprecated` version is now `0.50.0`
 
 #### Fixed