Cherry-pick of #2181. Notes below:

Platforms Impacted

• iOS
• visionOS
• macOS

Description of changes

Per https://forums.swift.org/t/warnings-as-errors-in-sub-packages/70810: Having this flag enabled in a sub-package causes conflicts with the automatic "-suppress-warnings" flag added by Xcode.

Verification

Builds and runs still, including as sub-package

Pull request checklist

This PR has considered:

• Light and Dark appearances
• iOS supported versions (all major versions greater than or equal current target deployment version)
• VoiceOver and Keyboard Accessibility
• Internationalization and Right to Left layouts
• Different resolutions (1x, 2x, 3x)
• Size classes and window sizes (iPhone vs iPad, notched devices, multitasking, different window sizes, etc)
• iPad Pointer interaction
• SwiftUI consumption (validation or new demo scenarios needed)
• Objective-C exposure (provide it only if needed)

Microsoft Reviewers: Open in CodeFlow

Microsoft Reviewers: Open in CodeFlow