[Godot4.3][iOS Plugin][xcode 16.2] Could not build module 'Foundation' and standard cpp errors for iOS plugin

### Tested versions

-Reproducible in the 4.3 branch.

### System information

Mac M4 - godot 4.3 - XCode 16.2

### Issue description

I'm trying to build a custom iOS plugin following [the steps here](https://docs.godotengine.org/en/stable/tutorials/platform/ios/ios_plugin.html#creating-an-ios-plugin) using XCode 16.2 and godot 4.3 (branch).

It fails to build the 'Foundation' module as well as the standard cpp classes. See screenshot below.

### Steps to reproduce

1. Have XCode 16.2
2. Checkout the [default iOS plugin template](https://github.com/naithar/godot_ios_plugin).
3. Switch godot sub-module to branch `4.3`.
4. build `godot` with `scons platform=ios target=template_debug generate_bundle=yes ios_simulator=yes`
5. Open plugin project
6. Update `Search Header Paths` to new paths (the default ones are outdated).
7. Build the library

### Minimal reproduction project (MRP)

Follow the [official steps](https://docs.godotengine.org/en/stable/tutorials/platform/ios/ios_plugin.html#creating-an-ios-plugin) for creating a plugin using the [default template](https://github.com/naithar/godot_ios_plugin). Only difference is using Godot 4.3 and XCode 16.

Start with the default godot_ios_plugin template and the documented iOS plugin steps, then reproduce the failure using the listed SCons command and Xcode 16.2. Inspect the plugin project's Search Header Paths and the Foundation and standard C++ build errors; done means the library builds successfully for the Godot 4.3 iOS setup.

Written by the indexing model from the issue text.