ansible: Set work dir for tar backups properly

ansible/skund.yml

@@ -150,6 +150,7 @@
               content: |
                 TARGET=backup-skund@127.0.0.1
                 SOURCES="/home/xstill/sync /home/xstill/recepty /home/xstill/_config /home/xstill/notes /data/xstill/repo-t14"
+                WORK_DIR=/root/backup-work
               dest: "/backup/skund/backup-tar.config"
 
           - name: "Authorized key for backup-skund"