heather: drop 'systemd, not container' from homepage descriptions

hosts/heather/arion-compose.nix

@@ -34,15 +34,15 @@ let
         - Syncthing:
             icon: syncthing.png
             href: https://sync.iscg.dev
-            description: File sync GUI (systemd, not container)
+            description: File sync GUI
         - tuwunel-admin:
             icon: matrix.png
             href: https://admin.iscg.dev
-            description: Matrix admin room UI (systemd, not container)
+            description: Matrix admin room UI
         - Pi Web:
             icon: /images/pi.png
             href: https://pi.iscg.dev
-            description: pi coding agent web UI (systemd, not container)
+            description: pi coding agent web UI
     - Communication:
         - Tuwunel:
             icon: matrix.png