update changelog before v7.3.2 release

CHANGELOG.md

@@ -34,22 +34,16 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 # Changelog
 
-## [[Unreleased]]
+## [v7.3.2](https://github.com/cosmos/ibc-go/releases/tag/v7.3.2) - 2024-01-31
 
 ### Dependencies
 
 * [\#5717](https://github.com/cosmos/ibc-go/pull/5717) Update Cosmos SDK to v0.47.8 and CometBFT to v0.37.4.
 
-### API Breaking
-
-### State Machine Breaking
-
 ### Improvements
 
 * (core) [\#5541](https://github.com/cosmos/ibc-go/pull/5541) Enable emission of events on erroneous IBC application callbacks by appending a prefix to all event type and attribute keys.
 
-### Features
-
 ### Bug Fixes
 
 * (apps/27-interchain-accounts) [\#4944](https://github.com/cosmos/ibc-go/pull/4944) Add missing proto interface registration.