Image promotion for cluster-api-gcp v1.8.1

Signed-off-by: cpanato <[email protected]>

Author: cpanato

registry.k8s.io/images/k8s-staging-cluster-api-gcp/images.yaml

@@ -23,3 +23,4 @@
     "sha256:a58a3f1ea714b47c78c292c592fec55d987077779b8e6a559585bb0c1f8612f4": ["v1.6.1"]
     "sha256:553009bdf598b0097b24d05c5e94542ef45e8d7c80c0af6d4f4a98f7edad9e86": ["v1.7.0"]
     "sha256:1553f3489f0d33da735d7271a1e75f175db3f8ec3d5142e02c4e256a5700bca5": ["v1.8.0"]
+    "sha256:9fd7d5d5791fced5b775d8cad35502d8dfe7a2e028f5eff5380219753aaa64d7": ["v1.8.1"]