Add Pyodide (WASM) wheel build and release asset

[ericmjl]

Summary

• Replaces the old "Build universal wheel for Pyodide" job (PYODIDE=1 + setup.py bdist_wheel --universal) with a proper pyodide-build + Emscripten job that produces a wasm32 wheel.
• Adds a job that uploads the Pyodide wheel to the GitHub Release as an asset when a release is published (PyPI does not yet accept wasm32 wheels).
• Adds optional dependency pyodide in pyproject.toml and documents the manual Pyodide build in the dev guide; no Pixi or other new tooling.
• Removes Pixi-only references: .pixi from pre-commit sphinx-lint args, and conda/mamba/pixi → conda/mamba in cmodule and troubleshooting docs.

Numba remains optional on wasm via existing environment markers, so the Pyodide wheel is micropip-installable without numba.

CI changes

• build_pyodide_wheel: Python 3.12, install pyodide-build, get Emscripten version, mymindstorm/setup-emsdk, pip install -e ".[pyodide]", pyodide build, upload pyodide_wheel artifact.
• upload_pyodide_to_release: On release published, download pyodide_wheel and attach to the release via softprops/action-gh-release.
• upload_pypi: No longer downloads or uploads the old universal_wheel; PyPI receives only sdist + cibuildwheel platform wheels.

Made with Cursor

[ricardoV94]

@ericmjl for future reference we prefer devs to contribute from their forks instead of working on the main repo directly

[ericmjl]

@ericmjl for future reference we prefer devs to contribute from their forks instead of working on the main repo directly

I'm pretty sure I'm working from my own fork 😄

[lucianopaz]

Wouldn't it be good to add a line some in the README.md or the docs landing page saying how to install on a wasm environment? Wouldn't users have to put in the full url of the github release to install?

[ricardoV94]

@ericmjl for future reference we prefer devs to contribute from their forks instead of working on the main repo directly

I'm pretty sure I'm working from my own fork 😄

You sure are, I wasn't seeing the ericmjl prefix before on my desktop. On the mobile I see

[ericmjl]

@lucianopaz addressed your comment too.

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[maresb]

@ericmjl, heads-up in case you didn't notice, there are lots of merge conflicts from your last force-push.

[ricardoV94]

just the branch target

[anutosh491]

Hi,

This is Anutosh here (Jupyterlite, LLVM, Clang, Clang-Repl & Emscripten-Forge maintainer/contributor)

I have successfully built numba & llvmlite for wasm. I spoke about upstreaming my patches in the Numba community call yesterday and we should be making progress there. For more technical details go through my comment here : numba/numba#3284 (comment)

You can try out Numba in Jupyterlite here : https://notebook.link/@anutosh491/numba

I had interacted with Thomas Wiecki (@twiecki) about 2 weeks back on my LinkedIn post talking about how PyTensor could benefit out of this.

Hence I went ahead and built PyTensor for wasm enabling Numba as PyTensor's WebAssembly linker.

Check it out here, I have hosted a simple demo notebook to start with : https://notebook.link/@anutosh491/PyTensor (enable the debug logs to see how numba functions in the backend)

cc @ricardoV94 @maresb @lucianopaz

Feel free to contact us (me, @SylvainCorlay or @MMesch) at QuantStack for more details. We are the main authors of Jupyterlite and would like to host a Jupyterlite notebook in PyTensor's readme. We should possibly be able to shift tutorials or examples that users want to try out in Jupyterlite itself.

[ericmjl]

Alrighty, @ricardoV94 and @maresb -- looks like we're in a good spot now.