[federation] Refactor CA bundle defaults to chained style in hook_controlplane_config

Address non-blocking review suggestions from evallesp and michburk on
ci-framework PR #3766.

Refactor _federation_ca_bundle_secret_name to use chained | default()
filters instead of nesting them. This removes the redundant trailing
| default('custom-ca-certs', true) and flattens the remaining nested
default into a more readable two-step chain:

  | default(cifmw_custom_ca_certs_secret_name, true)
  | default('custom-ca-certs', true)

Signed-off-by: Ade Lee <alee@redhat.com>
Co-Authored-By: Claude <noreply@anthropic.com>

Author: 2 people

roles/federation/tasks/hook_controlplane_config.yml

@@ -48,7 +48,7 @@
     _federation_ca_bundle_secret_name: >-
       {{
         ((_federation_oscp_info.resources | first).spec.tls | default({})).caBundleSecretName
-        | default(cifmw_custom_ca_certs_secret_name | default('custom-ca-certs', true), true)
+        | default(cifmw_custom_ca_certs_secret_name, true)
         | default('custom-ca-certs', true)
       }}
     _federation_oscp_has_ca_bundle: >-