Activate cache for the tests

[aloctavodia]

Now that we’re using pymc-distributions, the CI tests seem to take longer than before (though I’m not entirely sure). This might be due to longer compilation times. Once compiled, the functions run as fast as usual. Perhaps we could use a cache for CI that persists across sessions.

[ricardoV94]

Yeah numba first time compiling can be rather slow. How slow is the CI?

[aloctavodia]

I have not measured it, it just feels much slower.

[ricardoV94]

Seems to be ~23m vs ~5m before: https://github.com/arviz-devs/preliz/actions/workflows/test.yml

[ricardoV94]

I'll ask the bot to see if it sees some outlier: https://github.com/arviz-devs/preliz/actions/runs/24340476500/job/71067880623

We should add the show slowest n flag to the pytest in the CI

[ricardoV94]

Numba is falling back to object mode on xlogy0 and xlogx, we have to fix that. Otherwise numba can't even cache those graphs.