after flutter upgrade to 3.0, manifest.lock is deleted after "flutter pub get"

Question

I am super newbie on flutter and programming also on this side stack overflow too.

Few days ago, Like everybody know, Flutter had a big update.

After That, after Flutter Clean -> Flutter pub get,

Then, my 'manifest.lock' is auto deleted ("flutter project/ios/pods/manifest.lock")

So i have to remake that file every time I want to build on Xcode. ㄴ> I'm using the method from this article. (thank you always) Could not build application for the simulator for flutter

Anyway, I wan't to fix the origin of this problem. Is there anyone who can help me out from this?!