InDetDigitization: cmake cleanup, enable flake8

Frank Winklmeierrequested to merge
fwinkl/athena:fwinkl_20201125T143820 into master
  • Cleanup cmake configuration for InDetDigitization packages.
  • Remove unused external dependencies.
  • Enable flake8 and fix code.
  • Delete unused PixelDigitization/python/JobOptCfg.py.

Merge request reports