chore: update openiap apple version to 1.3.15 (#3149)

## Summary

- Sync with OpenIAP apple 1.3.15
- Includes watchOS platform compatibility fixes
- iOS 15 compatibility for priceFormatStyle API
- visionOS support for UIWindowScene

## Related

- OpenIAP PR: hyodotdev/openiap#81
- OpenIAP Release: https://cocoapods.org/pods/openiap

## Changes

- Update openiap-versions.json (apple: 1.3.14 → 1.3.15)
- NitroIap.podspec automatically uses new version

## Test Plan

- [x] `yarn typecheck` passes
- [x] `yarn test` passes (244 tests)
- [x] Pre-commit checks passed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

* **Chores**
  * Updated Apple component version to 1.3.15.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: hyochan

openiap-versions.json

@@ -1,5 +1,5 @@
 {
-  "apple": "1.3.14",
+  "apple": "1.3.15",
   "google": "1.3.28",
   "gql": "1.3.17",
   "docs": "1.3.17"