Make sure restic does not scan /proc (and fail if files disappear there)

This should have been prevented by --one-file-system, but restic has a bug.
So we need this workaround.

defaults/main.yml

@@ -50,6 +50,9 @@ backups:
     '/var/lib/php/sessions/*': true
     '/root/.ansible/*': true
     '/var/log/**/*.gz': true
+    # Workaround for https://github.com/restic/restic/issues/3366
+    '/proc': true
+    '/dev': true
   include_files:
     '/': true
   hooks: