LinuxServer Changes:
Extract picons during build instead of init.
tvheadend Changes:
update to ffmpeg 5.1.2
- ffmpeg_static will always compile with ffmpeg 5.1.2
- Makefile.ffmpeg added to 5.1.2
- src/muxer/muxer_libav.c: update 'AVOutputFrmat' to 'const AVOutputFrmat'
- src/transcoding/transcode/hwaccels/vaapi.c --> incorporated the struct from libavcodec/vaapi.h
- src/transcoding/transcode/video.c: update type for qdata_size