Fix some ansible-lint complaints.

roles/backup/tasks/main.yml

@@ -1,7 +1,7 @@
 - name: install borg
   apt:
     name: borgbackup
-    state: latest
+    state: latest # noqa package-latest
 
 - name: check if borg password is available
   stat: path="{{ borg_pwd_file }}"
@@ -9,7 +9,7 @@
 
 - name: dump borg password
   shell: echo -n "{{ borg_pwd }}" > "{{ borg_pwd_file }}" ; chmod 0600 "{{ borg_pwd_file }}"
-  no_log: True
+  no_log: true
   when: not borg.stat.exists
 
 - name: provide backup script
@@ -22,6 +22,7 @@
   copy:
     src: "{{ item }}"
     dest: "/etc/systemd/system/{{ item }}"
+    mode: 0644
   with_items:
     - backup.service
     - backup.timer