update containerd binary to v1.6.4

Notable Updates

- Update go-cni to fix teardown regression
- Fix broken SELinux relabeling for Kubernetes volume mounts

full diff: containerd/containerd@v1.6.3...v1.6.4

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 6e376e3)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

hack/dockerfile/install/containerd.installer

@@ -15,7 +15,7 @@ set -e
 # the binary version you may also need to update the vendor version to pick up
 # bug fixes or new APIs, however, usually the Go packages are built from a
 # commit from the master branch.
-: "${CONTAINERD_VERSION:=v1.6.3}"
+: "${CONTAINERD_VERSION:=v1.6.4}"
 
 install_containerd() (
 	echo "Install containerd version $CONTAINERD_VERSION"