Fix void checks in Geometry Buffers

[sebavan]

https://forum.babylonjs.com/t/when-the-ssr-forcegeometrybuffer-value-is-set-to-true-the-program-encounters-an-error/49757/4

[bjsplat]

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[bjsplat]

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[bjsplat]

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[bjsplat]

Visualization tests for WebGPU (Experimental)
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