Python 3.13 Incompatability

Python 3.13 removes "dead batteries" from the standard library, which includes the cgi module. The cgi module is a requirement of ete3.

This is a documented issue within the ete repo. However, there is minimal discussion of the subject.

I suggest commenting out the ete3 import statements and other uses. These mostly occur in 05-phylogeny-reconstruction.py and 07-biological-diversity.py