Update kodi role to use pkgs.qt-pinned.jellyfin-media-player instead of
pkgs.jellyfin-media-player. This decouples jellyfin from the main nixpkgs
update cycle, avoiding massive qt5webengine rebuilds when updating other
packages.
The qt-pinned namespace was added in commit 03f1692.
Closes: x-xiiep
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>