Building with WinML on Windows

For quite a while, I've been able to build onnxruntime-genai-winml using:
```
cmake --preset windows_x64_winml_relwithdebinfo -DWINML_SDK_VERSION=1.8.2091 -DUSE_GUIDANCE=OFF -DUSE_CUDA=OFF -DUSE_DML=OFF -DUSE_ROCM=OFF
```

But I've noticed that this has started failing:
```
-- ----- Building with WinML support -----
-- Downloading Microsoft.Windows.AI.MachineLearning 1.8.2091
CMake Error at cmake/nuget.cmake:47 (message):
install_nuget_package: Install failed with: Package
'Microsoft.Windows.AI.MachineLearning 1.8.2091' is not found in the
following primary source(s):
'C:\Users\rdmetca\.nuget\packages\,https://aiinfra.pkgs.visualstudio.com/PublicPackages/_packaging/ORT-Nightly/nuget/v3/index.json'.
Please verify all your online package sources are available (OR) package
id, version are specified correctly.

Call Stack (most recent call first):
cmake/ortlib.cmake:28 (install_nuget_package)
CMakeLists.txt:99 (include)

-- Configuring incomplete, errors occurred!
```

I noticed that `build.py` uses `-DWINML_SDK_VERSION=2.1.1`, so I tried that, but the build seems to keep popping up a sign-in window:

Is this 2.1.1 package something available publicly?

Start with cmake/nuget.cmake and the WinML setup in cmake/ortlib.cmake, then inspect CMakeLists.txt and build.py for the package source and WINML_SDK_VERSION values. Reproduce the Windows preset configuration and determine whether the referenced Microsoft.Windows.AI.MachineLearning versions and package feed are publicly accessible without sign-in.

Written by the indexing model from the issue text.