[Firebase AI] Pin transitive dependencies of swift-markdown-ui

[andrewheard]

Pinned the dependencies of swift-markdown-ui to match its Package.resolved:

• https://github.com/gonzalezreal/NetworkImage: 7aff8d1b31148d32c5933d75557d42f6323ee3d1
• https://github.com/swiftlang/swift-cmark: 3ccff77b2dc5b96b77db3da0d68d28068593fa53

This is an attempt to fix the error in the quickstart_framework_firebaseai job in the firebase-ios-sdk repo.

[ncooke3]

LGTM. Is it possible we can remove the need for this dependency by using AttributedString? https://developer.apple.com/documentation/Foundation/AttributedString#Creating-Attributed-Strings-with-Markdown

[andrewheard]

LGTM. Is it possible we can remove the need for this dependency by using AttributedString? developer.apple.com/documentation/Foundation/AttributedString#Creating-Attributed-Strings-with-Markdown

@ncooke3 Unfortunately we did consider that but the Markdown rendering in AttributedString is quite limited and doesn't cover all the Markdown returned by Gemini (e.g., tables).