Update CHANGELOG

Author: diemogebhardt

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 - Fixed a bug that would result in `list.unique` having quadratic runtime.
 - Fixed the implementation of `list.key_set` to be tail recursive.
+- Added `Uri.empty` constant representing an empty URI, useful as a starting
+  point for constructing URIs with minimal boilerplate.
 
 ## v0.53.0 - 2025-01-23