update changelog before v4.5.0 release

CHANGELOG.md

@@ -35,23 +35,13 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 All notable changes to this project will be documented in this file.
 
-## [[Unreleased]]
+## [v4.5.0](https://github.com/cosmos/ibc-go/releases/tag/v4.5.0) - 2023-10-03
 
 ### Dependencies
 
 * [\#4738](https://github.com/cosmos/ibc-go/pull/4738) Bump Cosmos SDK to v0.45.16.
 * [\#4782](https://github.com/cosmos/ibc-go/pull/4782) Bump ics23 to v0.9.1.
 
-### API Breaking
-
-### State Machine Breaking
-
-### Improvements
-
-### Features
-
-### Bug Fixes
-
 ## [v4.4.2](https://github.com/cosmos/ibc-go/releases/tag/v4.4.2) - 2023-05-25
 
 ### Bug Fixes