docs: update iOS universal links AASA file example to use components

[lamek]

Updated the apple-app-site-association JSON example to use the modern components key instead of the deprecated paths key, aligning with Apple's requirements for iOS 13+

#12362

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[gemini-code-assist]

Code Review

This pull request updates the Apple App Site Association (AASA) JSON example and instructions in the universal links documentation to use the modern components array instead of the deprecated paths array. The review feedback suggests a minor clarification to the explanation of the components dictionary keys and values to improve technical accuracy.

[flutter-website-bot]

Staged preview of the updated docs.flutter.dev site (updated for commit d18b85d):

https://flutter-docs-prod--docs-pr13670-fix-12362-qwfsd8gq.web.app

[flutter-website-bot]

Staged preview of the updated flutter.dev site (updated for commit d18b85d):

https://flutter-dev-230821--www-pr13670-fix-12362-u4bryei8.web.app