Update CHANGELOG

Signed-off-by: Fabio Di Fabio <fabio.difabio@consensys.net>

Author: fab-10

CHANGELOG.md

@@ -37,6 +37,7 @@
 - Update Web3j dependencies [#6811](https://github.com/hyperledger/besu/pull/6811)
 - Add `tx-pool-blob-price-bump` option to configure the price bump percentage required to replace blob transactions (by default 100%) [#6874](https://github.com/hyperledger/besu/pull/6874)
 - Log detailed timing of block creation steps [#6880](https://github.com/hyperledger/besu/pull/6880)
+- Expose transaction count by type metrics for the layered txpool [#6903](https://github.com/hyperledger/besu/pull/6903)
 
 ### Bug fixes
 - Fix txpool dump/restore race condition [#6665](https://github.com/hyperledger/besu/pull/6665)