Backends: Vulkan: fixed build with VK_NO_PROTOTYPES.

Amend bbc89b6 (#8600)

backends/imgui_impl_vulkan.cpp

@@ -183,6 +183,7 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkFreeDescriptorSets) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkFreeMemory) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetBufferMemoryRequirements) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetDeviceQueue) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetImageMemoryRequirements) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceProperties) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceMemoryProperties) \