Speed up make notebook

[wd60622]

The test_notebook action is slow and takes about 30 minutes to run. Largely due to actual sampling of models taking place.

I few the purpose of this action is to ensure they run without errors and not that they are "correct"

The scripts/run_notebooks/runner.py script already uses Parallel with n_jobs=-1 to run the notebooks in parallel.

Some ideas to speed up this action:

• Use the larger runners offered by GitHub: https://github.blog/changelog/2022-10-20-github-actions-larger-hosted-runners-are-now-automatically-created-for-customers/
• Patch pm.sample and other slow functions to return dummy values (pm.sample_prior_predictive)

I lean toward looking into mocking the pm.sample call in the notebook. We should be able to monkey patch this.

Any one else have any ideas?