openSUSE ImageMagick Key Update Fixes 20 Security Issues Emerging

## This update for ImageMagick fixes the following issues: * CVE-2026-28493: integer overflow in the SIXEL decoder leads to out-of-bounds write (bsc#1259446). * CVE-2026-28494: missing bounds checks in the morphology kernel parsing functions can lead to a stack buffer overflow (bsc#1259447). * CVE-2026-28686: undersized output buffer allocation in the PCL encoder can lead to a heap buffer overflow (bsc#1259448). * CVE-2026-28687: heap use-after-free vulnerability in the MSL decoder via a crafted MSL file (bsc#1259450). * CVE-2026-28688: heap use-after-free in the MSL encoder when a cloned image is destroyed twice (bsc#1259451). * CVE-2026-28689: `domain="path"` authorization is checked before final file open/use and allows for read/write bypass via symlink swaps (bsc#1259452).