Add flag for lite versions about fanshim-python

[nmstoker]

Also needs python3-dev for the installation to work on a fresh Buster lite install:
sudo apt-get install python3-dev

Without doing that, you get:

Best match: RPi.GPIO 0.6.5
Processing RPi.GPIO-0.6.5.tar.gz
Writing /tmp/easy_install-q2f014__/RPi.GPIO-0.6.5/setup.cfg
Running RPi.GPIO-0.6.5/setup.py -q bdist_egg --dist-dir /tmp/easy_install-q2f014__/RPi.GPIO-0.6.5/egg-dist-tmp-0cd30dse
source/py_gpio.c:23:10: fatal error: Python.h: No such file or directory
 #include "Python.h"
          ^~~~~~~~~~
compilation terminated.
error: Setup script exited with error: command 'arm-linux-gnueabihf-gcc' failed with exit status 1

[Gadgetoid]

I didn't realise lite versions ( Raspbian Lite? ) didn't include setuptools. I'd dropped the fallback import to distutils since it can cause problems with our packaging.

Attempted to rectify in 31b58d7

[haggistech]

would also need python-psutil and python3-psutil :)

[Gadgetoid]

I wonder if I should add python-rpi.gpio to the apt dependencies. Building a version from source from pip is a little overkill, and those packages tend to evade being updated- for better or worse.

[haggistech]

Would probably make sense as you say then it will be picked up in updates etc