add changelog

Author: thymikee

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - `[expect]` Compare DOM nodes even if there are multiple Node classes ([#8064](https://github.com/facebook/jest/pull/8064))
 - `[jest-worker]` `worker.getStdout()` can return `null` ([#8083](https://github.com/facebook/jest/pull/8083))
+- `[jest-reporters/jest-runner]` Serialize `changedFiles` passed to workers ([#8090](https://github.com/facebook/jest/pull/8090))
 
 ### Chore & Maintenance