mail/sympa: upgrade 6.2.44 -> 6.2.52

• Some scenarios and list creation templates for "intranet" use cases were made optional: They have been moved into samples/
• See also "upgrading notes" for details: https://sympa-community.github.io/manual/upgrade/notes.html There are special instructions when upgrading from 6.2.50 but this version did not hit the ports tree.

PR: 243050
Submitted by: Geoffroy Desvernay <dgeo@centrale-marseille.fr> (maintainer)
Relnotes: https://github.com/sympa-community/sympa/releases/tag/6.2.52