support webgpu on deno

[sigmaSd]

Feature request

deno supports webgpu (with --unstable-webgpu cli flag), would be great if device: webgpu used this, currently it just errors with unsupported device

Motivation

This would allow using webgpu serverside, which is currently not possible

Your contribution

I don't think I can submit a PR any time soon

[sigmaSd]

if I change this

transformers.js/src/backends/onnx.js

Line 86 in 746c8c2

supportedDevices.push('cpu');

to webgpu I get a different error

 deno --unstable-webgpu -A a.ts
No model specified. Using default model: "Xenova/distilbert-base-uncased-finetuned-sst-2-english".
dtype not specified for "model". Using the default dtype (fp32) for this device (webgpu).
error: Uncaught (in promise) Error: no available backend found. ERR: [webgpu] backend not found.
    at resolveBackendAndExecutionProviders (file:///home/mrcool/.cache/deno/npm/registry.npmjs.org/onnxruntime-common/1.21.0/dist/cjs/backend-impl.js:124:15)
    at eventLoopTick (ext:core/01_core.js:178:7)

this does return true in deno

deno repl --unstable-webgpu 
Deno 2.3.1

navigator && "gpu" in navigator
true