Prepare changelog for v3.42.2-rc.3

Author: RiotRobot

CHANGELOG.md

@@ -2006,6 +2006,12 @@ All Changes
  * [BREAKING] Refactor the entire build process
    [\#1113](https://github.com/matrix-org/matrix-js-sdk/pull/1113)
 
+Changes in [3.42.2-rc.3](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v3.42.2-rc.3) (2022-04-08)
+============================================================================================================
+
+## 🐛 Bug Fixes
+ * Make self membership less prone to races ([\#2277](https://github.com/matrix-org/matrix-js-sdk/pull/2277)). Fixes vector-im/element-web#21661.
+
 Changes in [3.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v3.0.0) (2020-01-13)
 ================================================================================================
 [Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v3.0.0-rc.1...v3.0.0)