use-of-uninitialized-value in jxl u32

use-of-uninitialized-value in jxl u32: a task in MiMo-V2.6-RL-harbor-cyber: MiMo-V2.6-RL Cyber (Harbor) (Harbor dataset). MemorySanitizer: use-of-uninitialized-value in function jxl u32 in file ffmpeg/libavcodec/jpegxl parse.c