Bump Pyodide version to 0.29.3

[bartbroere]

This PR bumps Pyodide and deals with the change from print and printErr to stdout and stderr respectively.

Update: The CI needed some work. What ubuntu-latest refers to changed since the last time this ran probably. It was necessary to pin it to Ubuntu 22 for now, to avoid Chromium sandbox issues. It was also necessary to pin the globally installed npm so the binary directory can be found and used for starlit. Both of these fixes might warrant some changes in the starlit project if we want to resolve them a bit more permanently.

[bartbroere]

I included some more changes in this PR, that change the project's structure somewhat. In testing often an old build from npm was tested instead of the changes made in the PR, which had the effect that CI could seem okay, even if it wasn't. I switched to yarn workspaces for the monorepo approach. Now it should use the versions of each package that are in the working directory instead of getting it from npm.

Every other changes was the result of going from one failed CI run to the next.

Hopefully this change works for you too.

[gzuidhof]

Thank you for the contribution!

I have not run it locally (I am not using Starboard for a project I'm working on since quite a while now..) - but the changes look good and with CI passing I'm happy to merge it :)