ReflectorNode: Remove getTextureNode().

[Mugen87]

Related issue: -

Description

This PR removes the method getTextureNode() from ReflectorNode since the class has no property textureNode.

ReflectorNode is extended from TextureNode so instances of ReflectorNode can directly be used without calling getTextureNode().

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	689.82 170.9	689.82 170.9	+0 B +0 B
WebGPU	812.49 218.86	812.45 218.85	-41 B -4 B
WebGPU Nodes	812 218.73	811.96 218.72	-41 B -4 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	462.84 111.78	462.84 111.78	+0 B +0 B
WebGPU	536.56 144.82	536.56 144.82	+0 B +0 B
WebGPU Nodes	492.68 134.55	492.68 134.55	+0 B +0 B