It is valid(*) for Vulkan drivers to only support one queue which can
accept both graphics and compute commands. If additional queues are
requested, keep assigning it to the last queue index of a valid queue
family, instead of failing to create the device.

(*) https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VkQueueFlagBits.html:
"If an implementation exposes any queue family that supports graphics
operations, at least one queue family of at least one physical device
exposed by the implementation must support both graphics and compute
operations."