add the line register_requested_device_extension(VK_KHR_EXTERNAL_MEMORY_WIN32_EXTENSION_NAME, true); on line 506 of drivers/vulkan/vulkan_context.cpp

You need Visual studio (with C++ and .NET support) and a Python 3.12 environment (or at least 3.7+) (I use conda for this)

Then just pip install scons

you can then build the whole thing with mono support using the following:

// Build Godot
scons p=windows vsproj=yes module_mono_enabled=yes

// Create the .NET bindings
"bin\godot.windows.editor.x86_64.mono.exe" --headless --generate-mono-glue modules/mono/glue

// Build the .NET assemblies
python "modules/mono/build_scripts/build_assemblies.py" --godot-output-dir=./bin