chore: pin version of Duplicati to 2.0.7

As this is based on a `linuxserver.io` [1] container image it makes
sense to use their `lscr.io` registry gateway service instead.

[1] https://www.linuxserver.io/

docker-compose/duplicati/docker-compose.yaml

@@ -1,7 +1,7 @@
 ---
 services:
   duplicati:
-    image: ghcr.io/linuxserver/duplicati
+    image: lscr.io/linuxserver/duplicati:2.0.7
     container_name: duplicati
     environment:
       - PUID=1000