TSL: Fix inconsistent chaining for .step() (Parameter order)

[sunag]

Closes #31205

Description

Fix inconsistent chaining for .step(). #31205 (comment)

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	337.4 78.67	337.4 78.67	+0 B +0 B
WebGPU	554.99 153.61	555.02 153.63	+33 B +23 B
WebGPU Nodes	554.34 153.46	554.38 153.48	+33 B +22 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	468.59 113.33	468.59 113.33	+0 B +0 B
WebGPU	630.02 170.38	630.03 170.39	+14 B +3 B
WebGPU Nodes	584.87 159.73	584.88 159.73	+14 B +3 B