Bug: duplicate vulkan devices being detected on windows

[tempstudio]

What happened?

When running llama-cli.exe for vulkan on Windows, it detects the same graphics card twice, which means it does not work out of the box.
by default it will try to use "both" which then leads to the cryptic error

MESA: error: == VALIDATION ERROR =============================================
error: Total Thread Group Shared Memory storage is 33792, exceeded 32768.
Validation failed.

Setting

$env:GGML_VK_VISIBLE_DEVICES=0

is necessary and works, but that's not really documented anywhere.

Name and Version

./llama-cli.exe --version
version: 3772 (23e0d70)
built with MSVC 19.29.30154.0 for x64

What operating system are you seeing the problem on?

Windows

Relevant log output

ggml_vulkan: Found 2 Vulkan devices:
Vulkan0: AMD Radeon RX 6800 XT (AMD proprietary driver) | uma: 0 | fp16: 1 | warp size: 64
Vulkan1: Microsoft Direct3D12 (AMD Radeon RX 6800 XT) (Dozen) | uma: 0 | fp16: 1 | warp size: 32