Update containerd v1.2.6

Signed-off-by: Jintao Zhang <zhangjintao9020@gmail.com>
(cherry picked from commit 8092cfb6e7396e0c5fc319b86ce9dca2246210f2)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

hack/dockerfile/install/containerd.installer

@@ -4,7 +4,7 @@
 # containerd is also pinned in vendor.conf. When updating the binary
 # version you may also need to update the vendor version to pick up bug
 # fixes or new APIs.
-CONTAINERD_COMMIT=bb71b10fd8f58240ca47fbb579b9d1028eea7c84 # v1.2.5
+CONTAINERD_COMMIT=894b81a4b802e4eb2a91d1ce216b8817763c29fb # v1.2.6
 
 install_containerd() {
 	echo "Install containerd version $CONTAINERD_COMMIT"