This is referenced by https://github.com/ostreedev/ostree-rs-ext/blob/9645cee4f29786ba51ae9d62a52eeef9230146fd/lib/src/globals.rs#L16 specifically used for the (container image) pull secret in `/run/ostree/auth.json`. Let's pre-create the directory so users don't have to. Motivated by https://github.com/openshift/machine-config-operator/pull/3007#discussion_r824172564