Copy edit "UISceneDelegate adoption" breaking change guide

[parlough]

Page URL

https://docs.flutter.dev/release/breaking-changes/uiscenedelegate/

Page source

https://github.com/flutter/website/tree/main/src/content/release/breaking-changes/uiscenedelegate.md

Describe the problem

The page needs a copy edit.

Expected fix

No response

Additional context

No response

I would like to fix this problem.

• [ ] I will try and fix this problem on docs.flutter.dev.