Dockerfile: bump up Podman from v4.0.2 to v4.0.3
Dockerfile: bump up Podman from v4.0.2 to v4.0.3

Release note: https://github.com/containers/podman/releases/tag/v4.0.3

Signed-off-by: Kohei Tokunaga <72a466a7d91579e23b8af87d6766ee221241ce87@gmail.com>

containerd/stargz-snapshotter,containerd/stargz-snapshotter,containerd/stargz-snapshotter,containerd/stargz-snapshotter