It seems the v0.8.0 container image was published, but not the accompanying Helm chart version. This is important because RBAC has changed and is missing from v0.7.1 of the Helm chart.
❯ helm repo add jetstack https://charts.jetstack.io --force-update
"jetstack" has been added to your repositories
❯ helm search repo cert-manager-google-cas-issuer
NAME CHART VERSION APP VERSION DESCRIPTION
jetstack/cert-manager-google-cas-issuer v0.7.1 v0.7.1 A Helm chart for jetstack/google-cas-issuer
It seems the v0.8.0 container image was published, but not the accompanying Helm chart version. This is important because RBAC has changed and is missing from v0.7.1 of the Helm chart.