Fix iOS packaging pipeline (#26426)
### Description
<!-- Describe your changes. -->
Change Xcode version from 16.4 to 16.2, according to what's available on
the build agent image.
Adjust casing in `xcodebuild -destination` argument.
### Motivation and Context
<!-- - Why is this change required? What problem does it solve?
- If it fixes an open issue, please link to the issue here. -->
Fix iOS packaging pipeline issues.
