Change python to python3

[DimitriPapadopoulos]

wtf/wtf.py

Line 1 in fe5618a

#!/usr/bin/env python

Some distributions such as Ubuntu 22.04 have only python3 installed by default, no python. Python 3 should be available on (almost) all developer machine nowadays:

$ wtf.py 
/usr/bin/env: 'python': No such file or directory
$