Revert "[chore] Release 4.10.0 (#522)" (#525)

This reverts commit b502f25.

Author: lahirumaramba

firebase.go

@@ -39,7 +39,7 @@ import (
 var defaultAuthOverrides = make(map[string]interface{})
 
 // Version of the Firebase Go Admin SDK.
-const Version = "4.10.0"
+const Version = "4.9.0"
 
 // firebaseEnvName is the name of the environment variable with the Config.
 const firebaseEnvName = "FIREBASE_CONFIG"