feat(framework) Update CHANGELOG for v1.15.1 (#4903)

Co-authored-by: jafermarq <[email protected]>
Co-authored-by: Taner Topal <[email protected]>

framework/docs/source/ref-changelog.md

@@ -1,6 +1,40 @@
 # Changelog
 
-## Unreleased
+## v1.15.1 (2025-02-05)
+
+### 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):
+
+`Dimitris Stripelis`, `Heng Pan`, `Javier`, `Taner Topal`, `Yan Gao` <!---TOKEN_v1.15.1-->
+
+### What's new?
+
+- **Improve time drift compensation in automatic SuperNode authentication** ([#4899](https://github.com/adap/flower/pull/4899))
+
+  In addition to allowing for a time delay (positive time difference), SuperLink now also accounts for time drift, which might result in negative time differences between timestamps in SuperLink and SuperNode during authentication.
+
+- **Rename constants for gRPC metadata** ([#4902](https://github.com/adap/flower/pull/4902))
+
+  All metadata keys in gRPC messages that previously used underscores (`_`) have been replaced with hyphens (`-`). Using underscores is not recommended in setups where SuperLink may be deployed behind load balancers or reverse proxies.
+
+- **Filtering out non-Fleet API requests at the `FleetServicer`** ([#4900](https://github.com/adap/flower/pull/4900))
+
+  The Fleet API endpoint will now reject gRPC requests that are not part of its API.
+
+- **Fix exit handlers mechanism for Windows** ([#4907](https://github.com/adap/flower/pull/4907))
+
+  The `SIGQUIT` [Python signal](https://docs.python.org/3/library/signal.html) is not supported on Windows. This signal is now excluded when Flower is executed on Windows.
+
+- **Updated Examples** ([#4895](https://github.com/adap/flower/pull/4895), [#4158](https://github.com/adap/flower/pull/4158), [#4879](https://github.com/adap/flower/pull/4879))
+
+  Examples have been updated to the latest version of Flower. Some examples have also had their dependencies upgraded. The [Federated Finetuning of a Whisper model example](https://github.com/adap/flower/tree/main/examples/whisper-federated-finetuning) has been updated to use the new Flower execution method: `flwr run`.
+
+- **Update FlowerTuneLLM Leaderboard evaluation scripts** ([#4919](https://github.com/adap/flower/pull/4910))
+
+  We have updated the package versions used in the evaluation scripts. There is still time to participate in the [Flower LLM Leaderboard](https://flower.ai/benchmarks/llm-leaderboard/)!
+
+- **Update Documentation** ([#4897](https://github.com/adap/flower/pull/4897), [#4896](https://github.com/adap/flower/pull/4896), [#4898](https://github.com/adap/flower/pull/4898), [#4909](https://github.com/adap/flower/pull/4909))
 
 ## v1.15.0 (2025-01-31)