prepare changelog for v4.2.0 release

CHANGELOG.md

@@ -34,22 +34,18 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 # Changelog
 
-## [Unreleased]
+## [v4.2.0](https://github.com/cosmos/ibc-go/releases/tag/v4.2.0) - 2022-11-07
 
 ### Dependencies
 
 * [\#2588](https://github.com/cosmos/ibc-go/pull/2588) Bump SDK version to v0.45.10 and Tendermint to v0.34.22.
 
-### API Breaking
-
 ### State Machine Breaking
 
 * (apps/transfer) [\#2651](https://github.com/cosmos/ibc-go/pull/2651) Introduce `mustProtoMarshalJSON` for ics20 packet data marshalling which will skip emission (marshalling) of the memo field if unpopulated (empty). 
 * (27-interchain-accounts) [\#2580](https://github.com/cosmos/ibc-go/issues/2580) Removing port prefix requirement from the ICA host channel handshake
 * (transfer) [\#2377](https://github.com/cosmos/ibc-go/pull/2377) Adding `sequence` to `MsgTransferResponse`.
 
-### Improvements
-
 ### Features
 
 * (apps/transfer) [\#2595](https://github.com/cosmos/ibc-go/pull/2595) Adding optional memo field to `FungibleTokenPacketData` and `MsgTransfer`.