WebGLGeometries: Don't upload morph target attributes.

[mrxz]

Description
Morph target attributes were being uploaded as DataTexture and as buffers. The latter seems to be left over from the WebGL1 fallback path. Since WebGL1 is no longer supported, it should be safe to remove this logic. With this change the morph targets now also consume less memory on the GPU.

This contribution is funded by Fern Solutions

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	339.37 79.06	339.14 78.99	-228 B -69 B
WebGPU	478.24 132.66	478.24 132.66	+0 B +0 B
WebGPU Nodes	477.71 132.54	477.71 132.54	+0 B +0 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	464.82 112.02	464.59 111.96	-228 B -57 B
WebGPU	546.92 148.19	546.92 148.19	+0 B +0 B
WebGPU Nodes	502.8 137.91	502.8 137.91	+0 B +0 B