fix(olm-subscriptions): Use kustomize create option for conditional startingCSV

Remove hardcoded startingCSV placeholder from base subscription and use
kustomize's `options.create: true` feature. This allows startingCSV to be
dynamically set only when a specific version is provided via ConfigMap.

When openstack-operator-version is empty (or "latest"), kustomize renders
startingCSV as null, which OLM interprets as "use channel head".

Changes:
- Remove startingCSV from base openstack-subscription.yaml
- Add create:true option to startingCSV replacement in kustomization.yaml

Assisted-By: Cursor (claude-4.5-opus)

Signed-off-by: Roberto Alfieri <ralfieri@redhat.com>

Author: rebtoor

lib/olm-openstack-subscriptions/overlays/default/kustomization.yaml

@@ -109,6 +109,8 @@ replacements:
           labelSelector: category=openstack-subscription
         fieldPaths:
           - spec.startingCSV
+        options:
+          create: true
   - source:
       kind: ConfigMap
       name: olm-values

lib/olm-openstack-subscriptions/overlays/default/openstack-subscription.yaml

@@ -12,4 +12,3 @@ spec:
   name: openstack-operator
   source: openstack-operator-index
   sourceNamespace: openshift-marketplace
-  startingCSV: openstack-operator.latest