Merge pull request #8273 from dgrisonnet/metrics-server-v0.8.0

metrics-server: image promotion for v0.8.0

Author: k8s-ci-robot

registry.k8s.io/images/k8s-staging-metrics-server/images.yaml

@@ -18,3 +18,4 @@
     "sha256:1c0419326500f1704af580d12a579671b2c3a06a8aa918cd61d0a35fb2d6b3ce": ["v0.7.0"]
     "sha256:db3800085a0957083930c3932b17580eec652cfb6156a05c0f79c7543e80d17a": ["v0.7.1"]
     "sha256:ffcb2bf004d6aa0a17d90e0247cf94f2865c8901dcab4427034c341951c239f9": ["v0.7.2"]
+    "sha256:89258156d0e9af60403eafd44da9676fd66f600c7934d468ccc17e42b199aee2": ["v0.8.0"]