AVIF with gainmap broken

AVIFs with a gainmap generated from avifgainmaputil in [libavif](https://github.com/AOMediaCodec/libavif) are displayed as pure white images; they don't even display in just SDR and seem to be broken in tev. normal AVIFs work fine and my gainmap AVIFs display fine in chrome here is the command i used: ```bash avifgainmaputil combine input-sdr.png input-hdr.png output-gainmap.avif -d 12 -q 100 --qalpha 100 -y 444 --depth-gain-map 12 --qgain-map 100 --cicp-alternate 9/16/9 --ignore-profile ```