WebGPURenderer: Refactor env map rotation.

[Mugen87]

Related issue: #33077

Description

Refactors the env map rotation logic in MaterialProperties and SceneProperties by using the cleaner matrix approach from #33077.

@WestLangley The code looks a bit different compared to WebGLRenderer since the flip is implemented in CubeTextureNode. Because of the way how the code is organized with nodes , I've sticked to the current approach and just fixed the order how transformation is applied (first rotation, then flip). That was definitely wrong in WebGPURenderer.

webgpu_materials_envmaps renders as webgl_materials_envmaps and even the user provided test case in #33077 (comment) renders correctly in WebGPURenderer.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	360.82 85.68	360.82 85.68	+0 B +0 B
WebGPU	632.76 175.53	632.7 175.45	-65 B -72 B
WebGPU Nodes	630.88 175.24	630.82 175.17	-65 B -69 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	493.02 120.25	493.02 120.25	+0 B +0 B
WebGPU	705.19 190.5	705.15 190.48	-47 B -18 B
WebGPU Nodes	654.41 177.78	654.37 177.74	-47 B -40 B