update containerd binary to v1.6.9

release notes: https://github.com/containerd/containerd/releases/tag/v1.6.9

full diff: containerd/containerd@v1.6.8...v1.6.9

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit ac79a02ace2d8432eafca4364b4c55a55aba5172)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

hack/dockerfile/install/containerd.installer

diff --git a/hack/dockerfile/install/containerd.installer b/hack/dockerfile/install/containerd.installer
index 5153427..2403e26 100755
--- a/hack/dockerfile/install/containerd.installer
+++ b/hack/dockerfile/install/containerd.installer
@@ -15,7 +15,7 @@
 # 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.
-: "${CONTAINERD_VERSION:=v1.6.8}"
+: "${CONTAINERD_VERSION:=v1.6.9}"
 
 install_containerd() (
 	echo "Install containerd version $CONTAINERD_VERSION"