Errors in core notebooks should fail doc build

[OriolAbril]

Seeing #6322 I realized that when execution of core notebooks fails, the doc build continues. The main goal in having the notebooks here in this repo and executing them with every doc build is to prevent the notebooks from ever having outdated code that no longer runs. We should update https://github.com/pymc-devs/pymc/blob/main/docs/source/conf.py to make sure errors in notebook execution fail the doc build.

I think https://myst-nb.readthedocs.io/en/latest/computation/execute.html#error-reporting-warning-vs-failure outlines the solution, but it needs to be done and checked.

[thomasaarholt]

I'll add here that this one failed too: https://www.pymc.io/projects/docs/en/stable/learn/core_notebooks/pymc_overview.html#pymc-overview

There's a KeyboardInterrupt that happens halfway down the page.

[OriolAbril]

Thanks, this might be due to that cell taking too long, there is nobody who can keyboardinterrupt sampling when readthedocs automatically parses and executes the notebooks 🤔