Get required Python packages from setup.py files
    
    The hard-set dependencies in the requirements.*.txt files left nearly no
    wiggle room for updates of dependencies and it required a ton of source
    file patching.
    
    By using the setup.py/setup.cfg instead, we install the minimum set of
    required packages (and shorten our list of BuildRequires) while allowing
    minor versions of some dependencies to advance.
    
    Signed-off-by: Major Hayden <major@mhtx.net>