Set vault_os_packages to empty list for Fedora CoreOS #402
Description
Currently vault_os_packages contains entries for Fedora CoreOS since Ansible reports ansible_os_family: RedHat for it, causing Ansible to load values from vars/RedHat.yml. Therefore the OS detection needs to be adjusted to correctly identify Fedora CoreOS, as it requires different variables (like vault_os_packages: []) as other Red Hat derivates.