Rotate changelog for 25.2.0 (hyperledger#8266)

Signed-off-by: Simon Dudley <simon.dudley@consensys.net>

CHANGELOG.md

@@ -1,6 +1,24 @@
 # Changelog
 
 ## Unreleased
+### Breaking Changes
+### Upcoming Breaking Changes
+- `MetricSystem::createLabelledGauge` is deprecated and will be removed in a future release, replace it with `MetricSystem::createLabelledSuppliedGauge`
+- k8s (KUBERNETES) Nat method is now deprecated and will be removed in a future release. Use docker or none instead.
+- `--Xsnapsync-synchronizer-flat-db-healing-enabled` is deprecated, use `--Xbonsai-full-flat-db-enabled` instead.
+- `--Xbonsai-limit-trie-logs-enabled` is deprecated, use `--bonsai-limit-trie-logs-enabled` instead.
+- `--Xbonsai-trie-log-pruning-enabled` is deprecated, use `--bonsai-limit-trie-logs-enabled` instead.
+- `--Xbonsai-trie-logs-pruning-window-size` is deprecated, use `--bonsai-trie-logs-pruning-window-size` instead.
+- Sunsetting features - for more context on the reasoning behind the deprecation of these features, including alternative options, read [this blog post](https://www.lfdecentralizedtrust.org/blog/sunsetting-tessera-and-simplifying-hyperledger-besu)
+    - Tessera privacy
+    - Smart-contract-based (onchain) permissioning
+    - Proof of Work consensus
+    - Fast Sync
+### Additions and Improvements
+### Bug fixes
+
+## 25.2.0
+
 ### Breaking Changes
 - `rpc-gas-cap` default value has changed from 0 (unlimited) to 50M. If you require `rpc-gas-cap` greater than 50M, you'll need to set that explicitly. [#8251](https://github.com/hyperledger/besu/issues/8251)
 ### Upcoming Breaking Changes