Update image_family on image-config-1.33.yaml

Author: elieserr

jobs/e2e_node/containerd/k8s-release-branches/image-config-1.33.yaml

@@ -1,5 +1,5 @@
 images:
   cos-dev:
-    image_family: cos-113-lts
+    image_family: cos-121-lts
     project: cos-cloud
     metadata: "user-data</home/prow/go/src/k8s.io/test-infra/jobs/e2e_node/containerd/init.yaml,cni-template</home/prow/go/src/k8s.io/test-infra/jobs/e2e_node/containerd/cni.template,containerd-config</home/prow/go/src/k8s.io/test-infra/jobs/e2e_node/containerd/config-systemd.toml"