Update changelog for 0.4.0

Author: object-Object

CHANGELOG.md

@@ -4,6 +4,16 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and [Pydantic's HISTORY.md](https://github.com/pydantic/pydantic/blob/main/HISTORY.md), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## `0.4.0` - 2025-08-31
+
+### Added
+
+* Added `/gh actions artifact` for looking up a specific GitHub Actions artifact.
+
+### Changed
+
+* Updated discord.py to `2.6.2`.
+
 ## `0.3.0` - 2025-08-25
 
 ### Added