WebGPU - support rendering to slice of a 3D texture

[mvaligursky]

new in Chrome 125: https://developer.chrome.com/blog/new-in-webgpu-125#render_to_slice_of_3d_texture

You can now render directly to slice(s) of 3D textures within render passes, expanding its capabilities beyond common 2D texture rendering, with the new depthSlice member in a GPURenderPassColorAttachment. This addition allows you for example to create voxel-based scenes and effects by rendering directly into 3D texture volumes. See issue dawn:1020.