Push multiple Docker tags for image in CD.

This will allow Kubernetes resources that only pull images occasionally
(i.e., k8s jobs) to point to a static tag name, "latest", that is updated
regularly. It also means we can refer to that image in the k8s config
tracked in the repo, instead of out-of-date images.

deploy/azure/crls-sync.yaml

@@ -12,7 +12,7 @@ spec:
           restartPolicy: OnFailure
           containers:
           - name: crls
-            image: pwatat.azurecr.io/atat:8f1c8b5633ca70168837c885010e7d66d93562dc
+            image: pwatat.azurecr.io/atat:latest
             command: [
               "/bin/sh", "-c"
             ]