CLSA-2026-1767799681 expat: Fix of 3 CVEs

Rebase to version 2.5.0 - CVE-2024-28757: prevent billion laughs attacks in isolated external parser part of 839, reject direct parameter entity recursion part of 839 - CVE-2025-59375: fix memory amplification and add allocation tracker - CVE-2013-0340: properly handle entities expansion...