multimedia/tautulli: Update 2.16.0 => 2.18.1

Changelog:
https://github.com/Tautulli/Tautulli/blob/v2.18.1/CHANGELOG.md

PR: 295759
Approved by: christer.edwards@gmail.com (maintainer, timeout 2 weeks)
Sponsored by: UNIS Labs
MFH: 2026Q3