Facter does not correctly detect that it is running inside of a podman container

Facter shows the system as physical even when running inside of a rootless podman container.

The system should detect that it is inside of a container and, ideally, note that it is rootless/rootful.

The following information seems relevant, but may not be a complete picture:

• There is a /run/.containerenv mountpoint
• The SELinux context of any of the root-level filesystems is container_file_t.
• The contents of /proc/self/cgroup contains libpod (rootful)

The first two seem to be consistent and the third is the only way that I can tell to determine if you're rootful or rootless.