CLSA-2026-1784902308 Fix CVE(s): CVE-2026-61863, CVE-2026-61870

SECURITY UPDATE: memory leak in the TIFF GROUP4 encoder on temporary file failure - debian/patches/CVE-2026-61863.patch: destroy the cloned huffmanimage when the temporary file cannot be created in WriteGROUP4Image in coders/tiff.c - CVE-2026-61863 SECURITY UPDATE: memory leak in the VIFF encoder...