[firebase-release] Removed change log and reset repo after 4.0.2 release

Author: google-oss-bot

CHANGELOG.md

@@ -1,4 +0,0 @@
-- Fix bug where [secret parameters](https://firebase.google.com/docs/functions/config-env#secret_parameters), defined using `defineSecret()`, were missing a `.value()` method (#1281)
-- Fix bug where v1/https was not exported (#1267)
-- Fix incorrect typeVersion export paths (#1287)
-- Revert removal of `\_\_trigger` (#1274)