vault: add error message for empty tarballs in python3.11+
Valentin's fix for iteration of empty tarballs in the tarfile stdlib module was merged and released in Python 3.11, so we need to handle that case properly.
staging instance, all data can be removed at all time
Valentin's fix for iteration of empty tarballs in the tarfile stdlib module was merged and released in Python 3.11, so we need to handle that case properly.