PassNode: Add compileAsync().

[Mugen87]

Fixed #31220.

Description

The PR makes it possible to precompile scene passes by introducing compileAsync() on PassNode level. Typical usage:

const scenePass = pass( scene, camera );
scenePass.setMRT( mrt( {
	output,
	emissive
} ) );

const outputPass = scenePass.getTextureNode( 'output' );
const emissivePass = scenePass.getTextureNode( 'emissive' );

// precompile pass after the configuration is complete

await scenePass.compileAsync( renderer );

So when the animation loop starts and the pass is rendered for the first time, the frame time should be lower due to the pre-compilation.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	338.37 78.9	338.37 78.9	+0 B +0 B
WebGPU	560.72 155.17	560.91 155.22	+198 B +47 B
WebGPU Nodes	559.64 154.96	559.84 155	+198 B +48 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	469.75 113.6	469.75 113.6	+0 B +0 B
WebGPU	635.88 172.08	636.08 172.13	+198 B +50 B
WebGPU Nodes	590.53 161.32	590.73 161.37	+198 B +50 B