greenwave: use FedoraCycleNumber for CoreOS policy

That way we don't have to keep updating this file when cutting GA. In
the period where there is no branched release, `{{FedoraCycleNumber+1}}`
conceptually refers to rawhide, though that's more properly covered by
the explicit `fedora-rawhide` version. But at least I don't think it
should do any harm.

Follow-up to 793349a98d ("greenwave: stop gating f39 updates for
CoreOS"), which has more context.

roles/openshift-apps/greenwave/templates/fedora.yaml

@@ -523,8 +523,8 @@ rules:
 --- !Policy
 id: "bodhiupdate_bodhipush_coreos"
 product_versions:
-  - fedora-40
-  - fedora-41
+  - fedora-{{FedoraCycleNumber}}
+  - fedora-{{FedoraCycleNumber+1}}
   - fedora-rawhide
 decision_contexts:
   - bodhi_update_push_testing_critical-path-coreos_critpath