Update Xcode version to 16

[defagos]

Description

Important

We should likely not merge this PR until Xcode 16.0 RC is available.

This PR updates Xcode version to 16.

Changes made

• Update Xcode version.
• Update fastlane to avoid build issue with Xcode 16.

Checklist

• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).

[defagos]

We sadly cannot use the new Xcode 16 synchronized folders because they are not yet supported by xcodeproj, leading to fastlane failing when archiving the projects.