fix: Updated CHANGELOG.md

Author: AnneGerlach

CHANGELOG.md

@@ -17,6 +17,8 @@ This changelog follows the principles of [Keep a Changelog](https://keepachangel
 
 ### Fixed
 
+- Allow partial CollectionDTO for UpdateCollection use case
+
 ### Removed
 
 - Removed date fields validations in create and update dataset use cases, since validation is already handled in the backend and SPA frontend (other clients should perform client side validation also). This avoids duplicated logic and keeps the package focused on its core responsibility.