WebGPURenderer: Honor layerUpdates for array textures

[ahaensler]

Description

The DataArrayTexture.layerUpdates is ignored in the WebGPU backend. This PR fixes this and enables partial updates. Layer updates are much smoother now and there is no stutter.

Unrelated to the PR - some points that people may find useful

• WebGPU limits depth to 256. Call WebGPURenderer({requiredLimits: { maxTextureArrayLayers: 2048 }} to increase the limit.
• You can use data arrays with BatchedMesh, but neither BatchNode.batchingIdNode nor instanceIndex will work for indexing. The correct index is found here. This node is not exposed yet in the API.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	359.49 85.34	359.49 85.34	+0 B +0 B
WebGPU	626.44 174.13	626.58 174.15	+142 B +28 B
WebGPU Nodes	625.02 173.88	625.16 173.91	+142 B +29 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	491.23 119.75	491.23 119.75	+0 B +0 B
WebGPU	700.07 189.13	700.21 189.16	+142 B +28 B
WebGPU Nodes	649.27 176.49	649.41 176.52	+142 B +28 B

[sunag]

This PR broken the webgpu_volume_lighting_traa example.

[Mugen87]

Side note: We need to make more WebGPU examples work with E2E tests.