Debug pyodide release artifacts (and pyodide build debug support)

[joemarshall]

🚀 Feature

It would be nice to have debug (-g3 I guess) builds of pyodide core and ideally packages included as separate files on the github release. It would be even nicer if pyodide build would have an option to build packages against debug builds also.

Motivation

Right now pyodide build inherits build settings from the main pyodide package ( #4690 ). Because of this building a package as debug is a pig unless you build your own pyodide from source and call pyodide build against it. If you do manage to get your package built as debug, there is also the pain that quite often in debugging it, you end up running into the internals of pyodide or libraries which don't have debug info included.

Implementation

1. Build of pyodide core and cpython with -g3 -o1 flags added to CI.
2. Support in pyodide-build for debug builds (i.e. downloading the debug xbuild environment based on that debug build.)
3. Optionally, lovely if possible, but not super important - build of packages with the same flags. (again as a distribution zip attached to the release)