Vulkan: Set Geometry Shader Capability

Vulkan already used geometry stages, but it wasn't set as backend
capability. This resulted that the shader builder didn't validate
shaders that uses geometry stages.

Pull Request: https://projects.blender.org/blender/blender/pulls/111139

source/blender/gpu/vulkan/vk_backend.cc

@@ -217,6 +217,7 @@ void VKBackend::capabilities_init(VKDevice &device)
   /* Reset all capabilities from previous context. */
   GCaps = {};
   GCaps.compute_shader_support = true;
+  GCaps.geometry_shader_support = true;
   GCaps.shader_storage_buffer_objects_support = true;
   GCaps.shader_image_load_store_support = true;