openxr_loader dll name on Windows

Hello!

There is currently [an openxr PR active at libsdl-org/SDL](https://github.com/libsdl-org/SDL/pull/11601) adding openxr support.
It has support for loading openxr dynamically using `LoadLibrary` on Windows and `dlopen` on other platforms (instead of linking against the library).

However, on Windows the name of the shared library is slightly different when building a debug binary. [This happens here](https://github.com/KhronosGroup/OpenXR-SDK/blob/781f2eab3698d653c804ecbd11e0aed47eaad1c6/src/CMakeLists.txt#L136-L146).
Clearly, `openxr_loader.dll` (without `d` suffix) is the preferred name, but there is concern (vcpkg) package users will get non-functioning openxr SDL support because of this.
The suffix is configurable, but package maintainers are often hesitant to change default: developers have them for a reason.

Is the `d` suffix still required?
Current CMake Visual Studio generators put the various configurations in different folders.

Start with the linked OpenXR-SDK src/CMakeLists.txt section and the Windows configuration behavior of CMake Visual Studio generators. Determine whether the debug `d` suffix is required for loader compatibility and establish the expected loader name or path for package users; done means the naming question has a clear, maintainer-approved resolution.

Written by the indexing model from the issue text.