TSL: Automatic RTT if procedural input ​​are used in bumpMap()

[sunag]

Closes #31804

Description

Automatic RTT if procedural input ​​are used in bumpMap()

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	338.24 79.14	338.24 79.14	+0 B +0 B
WebGPU	579.39 160.1	579.39 160.19	+2 B +89 B
WebGPU Nodes	578 159.86	578 159.95	-2 B +88 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	469.83 113.84	469.83 113.84	+0 B +0 B
WebGPU	649.09 175.75	650.6 176.21	+1.51 kB +454 B
WebGPU Nodes	603.2 164.92	604.71 165.35	+1.51 kB +427 B

[Mugen87]

webgpu_lights_physical and webgpu_materials_lightmap now throw this error:

Uncaught Error: THREE.TSL: texture( value ) function expects a valid instance of THREE.Texture().

[sunag]

Oh, I had forgotten that bumpMap uses a more robust system to make the samples, I have to think about this more deeply.