Add a test module for run_in_pyodide functions

[hoodmane]

This fixes some reflection tools. If we define a class A in the test,

1. A.__module__ is no longer "builtins"
2. sys.modules[A.__module__].__dict__ points back to our current global scope
3. __file__ now has the correct value

[hoodmane]

Not yet. Locally the test passes if I do

pytest tests/test_doctest.py

but if I pass -s it fails...

[hoodmane]

But it looks like it's failing for an unrelated reason and the test_doctest_run.py behavior is as expected with two passes and a failure. Hmm.

[ryanking13]

Seems like there was some change in pytest 8.0.0. When I downgrade pytest version to <8.0.0, the failing test passes.

I suspect some of the modifications we do at private attributes doesn't work anymore.

[hoodmane]

Okay, let's cap Pytest <8 and I'll look into fixing it in a followup.

[ryanking13]

Okay, let's cap Pytest <8 and I'll look into fixing it in a followup.

Sounds good to me. Probably we should find a way to not use pytester plugin which is the reason for the complex modifications we do in the setup step.