Switch to ubi9 base images

Author: enarha

.ko.yaml

@@ -1,4 +1,5 @@
 defaultBaseImage: gcr.io/distroless/static:nonroot
 baseImageOverrides:
-  github.com/openshift-pipelines/manual-approval-gate/cmd/approver: registry.access.redhat.com/ubi8/ubi-minimal
-  github.com/openshift-pipelines/manual-approval-gate/cmd/controller: registry.access.redhat.com/ubi8/ubi-minimal
+  github.com/openshift-pipelines/manual-approval-gate/cmd/approver: registry.access.redhat.com/ubi9/ubi-minimal
+  github.com/openshift-pipelines/manual-approval-gate/cmd/controller: registry.access.redhat.com/ubi9/ubi-minimal
+  github.com/openshift-pipelines/manual-approval-gate/cmd/webhook: registry.access.redhat.com/ubi9/ubi-minimal