DX12 takes a long time to initialize the pipeline

The source seems to be the creation of the BC6H pipeline. It takes much longer on DX12 and all other variants.

```rust
        Self::create_pipeline(
            &device,
            &shader_module_bc6h,
            &mut bind_group_layouts,
            &mut pipelines,
            CompressionVariant::BC6H(BC6HSettings::basic()),
        );
```