Security Fix : CVE-2024-45492 in libexpat library

[KIMDONGYEON00]

Description

Fixes CVE-2024-45492 integer overflow vulnerability in bundled libexpat library's nextScaffoldPart function. Adds overflow check to prevent buffer overflow when parsing maliciously crafted XML data on 32-bit platforms.

• Added integer overflow check in nextScaffoldPart function
• Applied upstream patch from libexpat commit 9bf0f2c
• Prevents potential RCE through XML parsing

Security Impact:

• Fixes HIGH severity vulnerability (CVSS 7.3)
• Prevents buffer overflow on 32-bit systems
• No breaking changes to existing functionality

[AppVeyorBot]

❌ Build Slic3r 1.3.0-master-2520 failed (commit eebf008f2f by @KIMDONGYEON00)