Roundcube - Security updates 1.6.12

[Ralph]

This is a security update to the stable version 1.6 of Roundcube Webmail.
It provides fixes to recently reported security vulnerabilities:
- Fix Cross-Site-Scripting vulnerability via SVG's animate tag reported by Valentin T., CrowdStrike.
- Fix Information Disclosure vulnerability in the HTML style sanitizer reported by somerandomdev.
https://github.com/roundcube/roundcubem ... tag/1.6.12
https://roundcube.net/news/2025/12/13/s ... and-1.5.12