Profiling build_linux_image.sh: 96 s, of which 51 s in the dependency audit.
appimage_is_elf_file() ran file(1) and grep per candidate. An AppDir holds ~9.6k
of them, 4.8k being the bundled Python runtime, none of them ELF: ~19k processes
for 14 s. Read the four-byte magic instead; checked against the old result on
4000 files, no disagreement.
The dependency walk popped its queue with "${queue[@]:1}", which rebuilds the
whole array each time. At ~4.8k entries that was 22 s of copying. Use a read
index.
96 s -> 12.7 s. The audit still passes.
ExPikaPaka
bd0ef35b90