docs: add changelog entry for #9401

Author: taeold

CHANGELOG.md

@@ -1,3 +1,4 @@
+- Fixed an issue where the emulator would fail to start when using `firebase-functions` v7+ (#9401).
 - Added `functions.list_functions` as a MCP tool (#9369)
 - Added AI Logic to `firebase init` CLI command and `firebase_init` MCP tool. (#9185)
 - Improved error messages for Firebase AI Logic provisioning during 'firebase init' (#9377)