CLSA-2026-1781619427 libxml2: Fix of 4 CVEs

CVE-2023-29469: guard xmlDictComputeFastKey against namelen = 0 to prevent out-of-bounds read when hashing zero-length or negative-length keys - CVE-2023-45322: fix use-after-free in xmlNodeDumpOutputInternal triggered by malformed XML when default error handler interacts with freed memory -...