Package update libgdk-pixbuf in branch sisyphus

Multiple integer overflows in the (1) pixops_composite_nearest, (2) pixops_composite_color_nearest, and (3) pixops_process functions in pixops/pixops.c in gdk-pixbuf before 2.33.1 allow remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted image, which triggers a heap-based buffer overflow.