We added `use_modular_headers!` to our `Podfile`s as we originally planned to phase out `use_frameworks!` (see https://github.com/flutter/flutter/pull/42204). However, our plans have now changed and we are instead phasing out CocoaPods entirely in favor of Swift Package Manager.
CocoaPods's `use_frameworks!` and `use_modular_headers!` are two different overlapping options that should not be used together. This change removes the `use_modular_headers!` from the macOS `Podfile` and the iOS Swift `Podfile` (the iOS Objective-C template was recently deprecated https://github.com/flutter/flutter/pull/155867).
This change only affects _new_ Flutter apps. This change does not include an automatic migration as that could break existing apps. Instead, users are encouraged to migrate from CocoaPods to Swift Package Manager.
https://github.com/flutter/flutter/issues/156259
Increases the minimum macOS deployment target from macOS 10.13 (High Sierra) to 10.14 (Mojave) in the macOS app templates.
Includes:
* Update migration for macOS 10.11 apps to upgrade to 10.14
* Adds migration for macOS 10.13 apps to upgrade to 10.14
* Apply migration to all examples, and integration tests
This does not increase version in the plugin templates since those will need to wait until the 10.14 framework rolls to stable channel, so new plugins can build with apps created with `flutter create` on stable channel.
Issue: https://github.com/flutter/flutter/issues/114445
See RFC: http://flutter.dev/go/flutter-drop-macOS-10.13-2022-q4
See previous patch: https://github.com/flutter/flutter/pull/107689
