WebGPUBackend: Fix Occlusion Query Logic

[ycw]

Occlusion query result 0 = no samples pass = occluded, but current assertion is non-0 = occluded

Demo the issue: https://threejs.org/examples/#webgpu_occlusion,

In the demo, occluded color is set to blue, non-occluded color is set to green, so when the sphere is fully occluded, the plane should be in blue, not green

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	339.51 79.09	339.51 79.09	+0 B +0 B
WebGPU	490.94 136.33	490.94 136.33	+2 B +4 B
WebGPU Nodes	490.41 136.21	490.41 136.22	+2 B +7 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	465.35 112.14	465.35 112.14	+0 B +0 B
WebGPU	560.24 151.73	560.24 151.74	+2 B +3 B
WebGPU Nodes	516.33 141.52	516.34 141.52	+2 B +4 B

[Mugen87]

In the demo, occluded color is set to blue, non-occluded color is set to green, so when the sphere is fully occluded, the plane should be in blue, not green

In this case, do you mind changing the description text of the example? It would be great if you could regenerate the E2E screenshot of webgpu_occlusion.

Besides, does the WebGL backend also needs this fix? Sorry, I'm currently not into the occlusion query code. Hopefully someone else can additionally review this PR.

[sunag]

I inverted the colors in the example. Added the fix to WebGLBackend too.

[ycw]

Thanks