chore: Changelog

Author: Icebluewolf

CHANGELOG.md

@@ -44,6 +44,8 @@ These changes are available on the `master` branch, but have not yet been releas
   ([#3105](https://github.com/Pycord-Development/pycord/pull/3105))
 - Fixed the update of a user's `avatar_decoration` to now cause an `on_user_update`
   event to fire. ([#3103](https://github.com/Pycord-Development/pycord/pull/3103))
+- Fixed backend logic for `sync_commands` to only sync when needed.
+  ([#2990](https://github.com/Pycord-Development/pycord/pull/2990))
 
 ### Deprecated