Upgrade Roundcube to 1.6.10 and MariaDB to 10.11.11

[stephdl]

Brief description
We request to upgrade the Roundcube webmail application and its underlying MariaDB database to the following versions:

• Roundcube 1.6.10
• MariaDB 10.11.11

WHY: These updates address known security vulnerabilities, bug fixes, and improve compatibility with modern web standards and SQL features.

PURPOSE: Ensure secure and stable webmail functionality backed by a reliable, up-to-date SQL engine.

Proposed solution

Upgrade the Roundcube package or Docker image to v1.6.10.

Upgrade the MariaDB package or Docker image to v10.11.11.

Alternative solutions
Remaining on previous versions is discouraged due to potential security issues and limited support for newer browsers, email clients, and SQL features. Backporting patches is not sustainable in this case.

Additional context
Roundcube 1.6.10 includes essential security patches and UI refinements.
MariaDB 10.11.11 is a recent LTS release, offering continued support and enhanced SQL performance.
Together, these upgrades strengthen the reliability and security of the user-facing mail experience.

[stephdl]

see https://github.com/roundcube/roundcubemail/blob/master/CHANGELOG.md#release-1610

[stephdl]

QA

target version is ghcr.io/nethserver/roundcubemail:2.0.7-dev.1

• install an account provider and the mail stack
• direct install, no expected issue
• upgrade from ghcr.io/nethserver/roundcubemail:2.0.6 to ghcr.io/nethserver/roundcubemail:2.0.7-dev.1, no expected issue