Upgrade SOGo to 5.12.1

[stephdl]

Upgrade SOGo to 5.12.1

Proposed solution
Upgrade SOGo to version 5.12.1 to benefit from bug fixes, security patches, and feature improvements.

Alternative solutions
Remain on the current version, but this may expose known issues or limit future compatibility.

Additional context
See the SOGo changelog for details on version 5.12.1.

[stephdl]

QA

test the direct install and the upgrade of sogo to ghcr.io/nethserver/sogo:2.0.8-dev.1

database upgrade to 10.11.11 (minor upgrade)
sogo update to 5.12.1 (minor upgrade)

[stephdl]

verified at https://community.nethserver.org/t/sogo-5-12-1-needs-testers/25836/2