Update lcms2 to 2.19.1 - #394

…#651 follow-up) (#753)

#651 contained a real write-outside-dest vuln in prefix-stripped extraction,
but its symlink/hardlink handling is stricter than it needs to be: a link
whose *target* escapes dest_dir aborts the whole extraction. Legitimate
upstream tarballs ship exactly that in test fixtures — next.js
(test/.../node_modules symlinks) and syft (symlink-resolution testdata) —
so any rebuild of those packages now fails to extract at all (first hit by
gominimal/pkgs#394/#402, whose dep bumps cascade into next/syft).

Skip the offending link (with a warning) instead of erroring. This is
equally safe against the write-through vector: the link is never created,
so a later entry that would have written through it resolves to a contained
regular path under dest_dir. The entry-path escape stays a hard error — a
file writing to ../x has no benign form.

Tests: extract_rejects_escaping_symlink becomes extract_skips_escaping_symlink
(link skipped, siblings still extract), plus a new
skipping_escaping_symlink_still_contains_write_through proving the tar-slip
defense holds through the skip.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>