use-of-uninitialized-value in HEIF colorspace to string

use-of-uninitialized-value in HEIF colorspace to string: a task in MiMo-V2.6-RL-oss: Agentic RL Environments (MiMo RL release). MemorySanitizer: use-of-uninitialized-value in function HEIF colorspace to string in file graphicsmagick/coders/heif.c