chore: update changelog for release

Author: MangelMaxime

src/Vitest/CHANGELOG.md

@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## 1.0.0-rc.2 - 2025-10-20
+
+### Changed
+
+- PR #680: Add support for optional message in expect API (by @MangelMaxime)
+
 ## 1.0.0-rc.1 - 2025-09-18
 
 ### Added