Upgrade to Xcode 26 (#29468)
### Description
<!-- Describe your changes. -->
Update most Apple pipelines to use Xcode 26. Keep a build on Xcode 16
for coverage of the older toolchain.
Other fixes:
- Patch XNNPACK to fix an iphonesimulator x86_64 build error with the
newer iphonesimulator SDK.
- Fix issue where object files were not copied from the right location
for the Mac Catalyst static framework build.
### 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. -->
Upgrade to a newer Xcode version. Xcode 16 is no longer available on
some build images.
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
