yt-dlp has diverged from youtube-dl sufficiently that package inheritance hinders package maintenance. * gnu/packages/video.scm (yt-dlp): Don't inherit from YOUTUBE-DL. [build-system, synopsis, license]: New fields. [arguments]: Adjust accordingly. [inputs]: Add FFMPEG. Change-Id: I14c4cfb6a75ba0421c62eac778072ab3e76c72a1