update changelog before v7.5.0 release

CHANGELOG.md

@@ -34,14 +34,12 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 # Changelog
 
-## [[Unreleased]]
+## [v7.5.0](https://github.com/cosmos/ibc-go/releases/tag/v7.5.0) - 2024-05-14
 
 ### Dependencies
 
 * [\#6254](https://github.com/cosmos/ibc-go/pull/6254) Update Cosmos SDK to v0.47.11 and CometBFT to v0.37.5.
 
-### API Breaking
-
 ### State Machine Breaking
 
 * (light-clients/07-tendermint) [\#6276](https://github.com/cosmos/ibc-go/pull/6276) Fix: No-op to avoid panicking on `UpdateState` for invalid misbehaviour submissions.
@@ -60,6 +58,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
+* (apps/29-fee) [\#6255](https://github.com/cosmos/ibc-go/pull/6255) Delete already refunded fees from state if some fee(s) cannot be refunded on channel closure. 
+
 ## [v7.4.0](https://github.com/cosmos/ibc-go/releases/tag/v7.4.0) - 2024-04-05
 
 ## [v7.3.2](https://github.com/cosmos/ibc-go/releases/tag/v7.3.2) - 2024-01-31