Use variableDescriptorCount to avoid the pipeline recreation.

[stripe2933]

Instead of create the graphics pipelines with fixed amount of texture descriptor sets, use variable descriptor count to create pipelines only once and only re-allocate the descriptor set. This can make the asset loading time faster.

[stripe2933]

Looks like MoltenVK cannot handle this.

[mvk-error] SPIR-V to MSL conversion error: Argument buffer resource base type could not be determined. When padding argument buffer elements, all descriptor set resources must be supplied with a base type by the app.
[mvk-error] VK_ERROR_INVALID_SHADER_NV: Fragment shader function could not be compiled into pipeline. See previous logged error.
libc++abi: terminating due to uncaught exception of type vk::InvalidShaderNVError: Device::createGraphicsPipeline: ErrorInvalidShaderNV

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This error does not occur when Metal Argument Buffer is disabled. For this case, the binding count must be set to ≤ 14, since maxPerStageDescriptorSamplers is 16 and 2 slots are already bound.

Related upstream issue

[stripe2933]

Resolved by disabling the variable descriptor count feature in macOS.