install - fix filename (.list is automatically add)

tasks/install.yml

@@ -10,7 +10,7 @@
   become: true
   apt_repository:
     repo: "{{ pbs_repo_no_subscription }}"
-    filename: pbs-client.list
+    filename: pbs-client
 
 - name: proxmox backup client | update APT Cache
   apt: