notebook: Bayes Factor; run using pymc v5 (#490)

* nb: bayes-factor, run pymc v5

* adding myst file

* rerun Bayes Factor nb with pymc v5

* add author; rerun

* adding myst file

* re-execute to attempt reproducing the error

Co-authored-by: Oriol (ZBook) <oriol.abril.pla@gmail.com>

Author: reshamas