[Web] no training with wasm on node

[tharvik]

Describe the issue

I'm trying to train using onnxruntime-web on NodeJS but no wasm backend seems to work.
note: why not onnxruntime-node you ask? I want to run on both web and node, which based on the readme, should be supported; it's also why I'm using ESM instead of CommonJS.

sadly, I wasn't able to find a single version that works. and it isn't really clear which path should be imported. here goes a table of the error when trying to create a TrainingSession.

onnxruntime-web version	import path	error
1.17, 1.18		failed to asynchronously prepare wasm: LinkError: WebAssembly.instantiate(): Import #46 module="a" function="a": memory import must be a WebAssembly.Memory object
1.17, 1.18	/training	Error: no available backend found. ERR: [wasm] ReferenceError: __dirname is not defined, [cpu] Error: previous call to 'initWasm()' failed. (loaded via ESM where __dirname doesn't exists)
1.19, 1.20, dev		Error: Training backend could not be resolved. Make sure you're using the correct configuration & WebAssembly files.
1.19, 1.20, dev	/training	Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './training' is not defined by "exports" in [...]/node_modules/onnxruntime-web/package.json imported from [...]/[eval1]

also, 1.20 doesn't ship ort-training-wasm-simd-threaded.{wasm,mjs} anymore, which seems to be intended as per the release ("All ONNX Runtime Training packages have been deprecated"). but I don't see a web package with training in the new pkgs.

To reproduce

#!/bin/sh -eu

readonly VERSION=dev
readonly IMPORT=onnxruntime-web

npm init --yes
npm pkg set type=module
npm install "onnxruntime-web@${VERSION}"

node --experimental-default-type=module <<-EOF
import * as ort from "${IMPORT}";
await ort.TrainingSession.create({});
EOF

Urgency

that does block the ONNX support I wanted to provide in addition to TFJS. so bothering but not vital.

ONNX Runtime Installation

Released Package

ONNX Runtime Version or Commit ID

1.20, dev

Execution Provider

'wasm'/'cpu' (WebAssembly CPU)

[guschmue]

Sorry, we have stopped supporting training for ort-web since there wasn't much users for it.