[various] Add Swift Package Manager integration to example apps (#8219)
This migrates various example apps to have Swift Package Manager integration. This raises the example apps' Flutter SDK requirement to 3.24.0 or higher.
I will get a text exemption for this change.
The example apps were migrated using the following commands:
```
dart run script/tool/bin/flutter_plugin_tools.dart build-examples --ios --swift-package-manager
dart run script/tool/bin/flutter_plugin_tools.dart build-examples --macos --swift-package-manager
```
â ï¸ The following plugins' example apps are **not* included in this change as their migration included non-SPM changes that require closer review:
1. google_sign_in
1. google_sign_in_ios
1. image_picker
1. image_picker_ios
1. image_picker_macos
1. pigeon
Part of: https://github.com/flutter/flutter/issues/159173
[various] Update min macOS versions (#3987)
- Updates all macOS plugins to 10.14 as a minimum version, matching Flutter stable.
- Checks in the results of building all macOS examples with stable to bring them up to current with auto-migrations (and in some cases, with having ever been built, in the case of some examples with plugins where the CocoaPods changes were never committed).
All Runner.xcodeproj and Runner.xcworkspace changes are 100% tool-generated.
Also updates the repo tooling to know about a few more build-only example files that should not be flagged as potentially interesting for changelogs.
[various] Migrate example apps' AppDelegate.swift (#8155)
Migrated by running:
```
dart run script/tool/bin/flutter_plugin_tools.dart build-examples --ios --swift-package-manager
dart run script/tool/bin/flutter_plugin_tools.dart build-examples --macos --swift-package-manager
```
Tests aren't updated as this change should not affect semantics. I will get a test exemption.
Part of https://github.com/flutter/flutter/issues/159173
Remove use_modular_headers! from Podfiles (#7796)
â ï¸ _This PR does not update packages' versions as it only affects unpublished parts of example apps and tests._
We added use_modular_headers! to our Podfiles 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 example apps' Podfiles. This change does not affect packages themselves.
Part of https://github.com/flutter/flutter/issues/156259