remove devel/spe

I'd like to remove:
- devel/spe
- devel/py-Checker (only consumer is devel/spe)

spe = "Stani's Python Editor" which is long abandoned upstream,
python2-only and there are many alternative editors for Python.

This will help with getting a few ports closer to being python3-only:
- security/py-cryptodome
- x11/py-wxPython

ok?