chore(deps): update dependency red-hat-openshift to v4.15.18

| datasource     | package           | from    | to      |
| -------------- | ----------------- | ------- | ------- |
| endoflife-date | red-hat-openshift | 4.15.16 | 4.15.18 |

.github/actions/rosa-create-cluster/action.yml

@@ -35,7 +35,7 @@ inputs:
     description: 'Version of the OpenShift to install'
     required: true
     # renovate: datasource=endoflife-date depName=red-hat-openshift versioning=semver
-    default: "4.15.16"
+    default: "4.15.18"
   replicas:
     description: 'Number of replicas for the ROSA cluster'
     required: true