vulkan: Set descriptorBindingStorageBufferUpdateAfterBind

vulkan: Set descriptorBindingStorageBufferUpdateAfterBind

It's necessary now that we use storage buffers for gradients:

[ VUID-VkDescriptorSetLayoutBindingFlagsCreateInfo-descriptorBindingStorageBufferUpdateAfterBind-03008 ] Object 0: handle = 0x1e72d70, type = VK_OBJECT_TYPE_DEVICE; | MessageID = 0x943cc552 | vkCreateDescriptorSetLayout(): pBindings[0] can't have VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT for VK_DESCRIPTOR_TYPE_STORAGE_BUFFER since descriptorBindingStorageBufferUpdateAfterBind is not enabled. The Vulkan spec states: If VkPhysicalDeviceDescriptorIndexingFeatures::descriptorBindingStorageBufferUpdateAfterBind is not enabled, all bindings with descriptor type VK_DESCRIPTOR_TYPE_STORAGE_BUFFER must not use VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT (https://www.khronos.org/registry/vulkan/specs/1.3-extensions/html/vkspec.html#VUID-VkDescriptorSetLayoutBindingFlagsCreateInfo-descriptorBindingStorageBufferUpdateAfterBind-03008)