[cd] update xcode version to 15.2

[nan-li]

Description

One Line Summary

Update our CD script to use xcode 15.2, necessary to build now with Live Activities and xcode 15 being the minimum.

Details

Motivation

Release 5.2.0 CD failed then passed after these changes

The CI is already using 15.2.

Scope

CD

Testing

Unit testing

Manual testing

Affected code checklist

• Notifications
  • Display
  • Open
  • Push Processing
  • Confirm Deliveries
• Outcomes
• Sessions
• In-App Messaging
• REST API requests
• Public API changes

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have included test coverage for these changes, or explained why they are not needed
• All automated tests pass, or I explained why that is not possible
• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
• I have reviewed this PR myself, ensuring it meets each checklist item

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This change is