Support Python 3.9 and 3.10

[matt-peters]

Adds support for newer versions of Python and sklearn > 1.0.0.

Fixes #110 #101 #109 #107

[rashadmoarref]

It'd be great if this PR gets some attention. I have verified that this branch builds on Python3.9 using below pre-requirements:

lxml==4.9.2
numpy==1.20.3
Cython==0.29.33

and that the default extract_content method works properly using below dependency versions:

joblib==1.2.0
scikit-learn==1.1.2

[ericluugg]

For anyone interested I've forked a 3.10 branch https://github.com/ericluugg/dragnet3.10

This is the highest I've been able to get the dependencies. Anything past scikit-learn 1.2.2 leads to errors unpickling old models

lxml==5.1.1
numpy==1.26.3
Cython==3.0.10
scipy==1.14.0
scikit-learn==1.2.2