SECURITY UPDATE: out-of-bounds read/write in ARM NEON palette expansion
debian/patches/CVE-2026-33636.patch: restrict the NEON loop in
png_do_expand_palette_rgba8_neon and png_do_expand_palette_rgb8_neon
(arm/palette_neon_intrinsics.c) to full chunks only, so rows whose
width is not a multiple of the chunk size no longer read or write
past the row buffer