Gemma3n browser support

[bil-ash]

Feature request

As mentioned in #1348 , gemma3n is currently not supported in web browser, so please bring web browser support.

Motivation

It is important because gemma3n is a very good model, both with text-only modality or with multimodality, would be nice to be able to run it client-side

Your contribution

None.
I tried converting gemma3n-2b to ONNX using the script in this repo, thinking that I might be able to contribute something, but the conversion failed.

[xenova]

Working on it! :)

[bil-ash]

@xenova onnxruntime is adding 2-bit quantization support for av2, avx512 and neon. Also, recent emscripten versions support avx2 intrinsics. If these 2 are combined to build onnxruntime with 2-bit quantized models inference support for wasm runtime, maybe gemma3n can be run in browser.