The initial support for nested containers (2d2a2ef277) worked on
my machine (tm) and even laptop, but does not work on fresh installs.
This is likely due to changes in where persistent configuration is
stored on the host between various podman versions; even though my
podman is fully updated, it uses configuration created long ago.
Make nested containers work on fresh installs by also configuring
/etc/containers/storage.conf. The important piece is to set graphroot
to the same location as the host.
Verified both on my machine and on a fresh install.
Closesscylladb/scylladb#25156