NodeBuilderState: Fix type of bindingsReference in createBindings().

[cmhhelgeson]

Related issue: #31674

Description

Fixes an instance where bindGroup's bindingReference was being passed a bindGroup rather than an array of Bindings[].

Currently using this as a test PR to see if this change might have any downstream effects, which I don't anticipate since bindingsReference only appears to be relevant to bindGroupLayout caching. This PR does not have any effect on performance in webgpu_tsl_wood.html, which suggests that the way Bindings are parsed may be more relevant to the caching issue than the bindingsReference containing a valid Bindings array. However, optimizing GPU resource caching will presumably still depend on the cache's keys containing consistently structured data.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	338.91 79.1	338.91 79.1	+0 B +0 B
WebGPU	575.53 158.8	575.55 158.81	+18 B +4 B
WebGPU Nodes	574.14 158.56	574.15 158.56	+18 B +3 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	470.7 113.91	470.7 113.91	+0 B +0 B
WebGPU	646.58 174.86	646.6 174.87	+18 B +5 B
WebGPU Nodes	600.76 164.04	600.78 164.05	+18 B +4 B

[cmhhelgeson]

Tested on a few more examples and everything looks good.