One of these days, we'll enable LTO for our builds by default...well, only partially.

lib-ffmpeg-support in mod-ffmpeg in the latest main prevents us from doing so. If we are able to get linked #FFmpeg and fix most of the redefinition warnings, _then_ we can proceed forward.

For the foreseeable future, we'll continue to enable loaded FFmpeg by default, but we would encourage packagers to use linked FFmpeg when available.