[Mac] Fix --use_xcode build with Nodejs binding (#24868)
### Description
<!-- Describe your changes. -->
Currently, the XCode build with nodejs binding(`--use_xcode`) always
fails on Mac.
```
./build.sh --config Debug --use_xcode --use_webgpu --build_shared_lib --build_nodejs --parallel --compile_no_warning_as_error --skip_submodule_sync --cmake_extra_defines CMAKE_OSX_ARCHITECTURES=arm64 --skip_tests
```
The root cause is that the dylib locates on `/Debug/Debug` not `/Debug`
with using XCode generator. For other generator(e.g. make, ninja), the
dylib locates on `/Debug` as expected.
Mac pipeline can pass because they didn't use XCode generator.
<img width="913" alt="image"
src="https://github.com/user-attachments/assets/e1203fdb-d88a-4c06-abad-b641d502237c"
/>
