Unexpected win32.shl Package When Building Open3D with CUDA on Windows (Python 64-bit, x64 Target)

### Checklist

- [x] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [x] For Python issues, I have tested with the [latest development wheel](https://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [x] I have checked the [release documentation](https://www.open3d.org/docs/release/) and the [latest documentation](https://www.open3d.org/docs/latest/) (for `main` branch).

### Steps to reproduce the issue

### Issue: Unexpected `win32.shl` Package During Open3D CUDA Build on Windows

I am building Open3D with CUDA support on Windows using Python 64-bit and targeting x64 architecture. Here are my steps:

1. **CMake Configuration:**
```powershell
cmake -G "Visual Studio 17 2022" -A x64 -DCMAKE_GENERATOR_PLATFORM=x64 -DBUILD_CUDA_MODULE=ON -DCMAKE_CUDA_ARCHITECTURES=75 -DBUILD_PYTHON_MODULE=ON -DPython3_ROOT=D:\CUDA_NEW\myvenv -DPython3_EXECUTABLE=D:\CUDA_NEW\myvenv\Scripts\python.exe -DCMAKE_INSTALL_PREFIX="D:\CUDA_NEW\Open3D_install" ..
```
2. **Verifying Python Architecture:**
```powershell
python -c "import platform; print(platform.architecture())"
```
Output:
```
('64bit', 'WindowsPE')
```

3. **Building the Package:**
```powershell
cmake --build . --config Release --target pip-package
```

### Problem:
Despite specifying x64 throughout the build process, the final release package includes a `win32.shl` file. This is unexpected because:
- I used **Python 64-bit**.
- The **CMake build was set to x64**.
- The **CMake generator was explicitly configured for x64 (`-A x64`)**.

Has anyone encountered this before? Is `win32.shl` just a generic Windows shell file, or does it indicate an actual architecture mismatch? Any insights would be appreciated!

---

### Error message

```shell
It will shows the Warning like

opengl32.lib(OPENGL32.dll) : warning LNK4006: glPointSize already defined in bluegl.lib(BlueGLCoreWindowsImpl.obj); sec ond definition ignored [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj] opengl32.lib(OPENGL32.dll) : warning LNK4006: glPolygonMode already defined in bluegl.lib(BlueGLCoreWindowsImpl.obj); s econd definition ignored [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj] opengl32.lib(OPENGL32.dll) : warning LNK4006: glPolygonOffset already defined in bluegl.lib(BlueGLCoreWindowsImpl.obj); second definition ignored [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj] opengl32.lib(OPENGL32.dll) : warning LNK4006: glLineWidth already defined in bluegl.lib(BlueGLCoreWindowsImpl.obj); sec ond definition ignored [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj] opengl32.lib(OPENGL32.dll) : warning LNK4006: glBlendFunc already defined in bluegl.lib(BlueGLCoreWindowsImpl.obj); sec ond definition ignored [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj] opengl32.lib(OPENGL32.dll) : warning LNK4006: glGetIntegerv already defined in bluegl.lib(BlueGLCoreWindowsImpl.obj); s econd definition ignored [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj] opengl32.lib(OPENGL32.dll) : warning LNK4006: glGetString already defined in bluegl.lib(BlueGLCoreWindowsImpl.obj); sec ond definition ignored [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj] Creating library D:/CUDA_NEW/Open3D/build/lib/Release/Python/cuda/pybind.lib and object D:/CUDA_NEW/Open3D/build/l ib/Release/Python/cuda/pybind.exp D:\CUDA_NEW\Open3D\build\lib\Release\Python\cuda\pybind.cp39-win_amd64.pyd : warning LNK4088: image being generated due to /FORCE option; image may not run [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj]

Some warning Arine Exspecially
D:\CUDA_NEW\Open3D\build\lib\Release\Python\cuda\pybind.cp39-win_amd64.pyd : warning LNK4088: image being generated due to /FORCE option; image may not run [D:\CUDA_NEW\Open3D\build\cpp\pybind\pybind.vcxproj]
```

### Open3D, Python and System information

```markdown
Environment Details:

Operating System: Windows 11 64-bit
Python Version: Python 3.9 (output from import sys; print(sys.version))
Open3D Version: (output from print(open3d.__version__))
CUDA Version: 12.8
GPU: NVIDIA RTX 2050
System Architecture: x86_64
Is this a Remote Workstation? No
How did you install Open3D? Built from source
```

### Additional information

_No response_