Now that 0.35 has been released, we can consider increasing our minimum
required ffmpeg version. Currently, we think 4.4 is the most recent
version we can move to (from the current requirement of 4.0).
This allows us to remove a few conditionals. There are more that we
won't be able to remove unless we move further up to 5.1. 

Checking for JPEG XL support via libavcodec                               : no ('libavcodec >= 59.27.100' not found) 
Checking for new engine support for librubberband                         : no ('rubberband >= 3.0.0' not found) 
Checking for FFmpeg library                                               : no ('libavutil >= 56.70.100 libavcodec >= 58.134.100 libavformat >= 58.76.100 libswscale >= 5.9.100 libavfilter >= 7.110.100 libswresample >= 3.9.100' not found)