feat(framework) Update CHANGELOG for v1.15.2 (#4933)

framework/docs/source/ref-changelog.md

@@ -1,6 +1,30 @@
 # Changelog
 
-## Unreleased
+## v1.15.2 (2025-02-17)
+
+### Thanks to our contributors
+
+We would like to give our special thanks to all the contributors who made the new version of Flower possible (in `git shortlog` order):
+
+`Charles Beauville`, `Heng Pan`, `Javier`, `Leandro Collier`, `Stephane Moroso`, `Yan Gao` <!---TOKEN_v1.15.2-->
+
+### What's new?
+
+**Free processed messages in LinkState** ([#4934](https://github.com/adap/flower/pull/4934))
+
+When the ServerApp pulls the replies the SuperNodes sent to the SuperLink, these should be removed from the LinkState. In some situations, these weren't erased, which could lead to high memory utilization by the SuperLink.
+
+**Introduce Windows CI tests** ([#4908](https://github.com/adap/flower/pull/4908))
+
+We continue improving the experience of running Flower on Windows. Now, an automated CI test is run to ensure compatibility.
+
+**Update Ray version (Simulation Engine)** ([#4926](https://github.com/adap/flower/pull/4926))
+
+The Simulation Engine has been upgraded to a version of Ray that is compatible with Python 3.12.
+
+- **Update Documentation** ([#4915](https://github.com/adap/flower/pull/4915), [#4914](https://github.com/adap/flower/pull/4914))
+
+- **Other quality improvements** ([#4935](https://github.com/adap/flower/pull/4935), [#4936](https://github.com/adap/flower/pull/4936), [#4928](https://github.com/adap/flower/pull/4928), [#4924](https://github.com/adap/flower/pull/4924), [#4939](https://github.com/adap/flower/pull/4939))
 
 ## v1.15.1 (2025-02-05)