gitlab: add missing job inheritance for codestyle

The previous fix:

  commit b069efe2
  Author: Daniel P. Berrangé <berrange@redhat.com>
  Date:   Fri Jun 14 19:57:06 2024 +0100

    gitlab: fix codestyle CI job

was incomplete, as the job inheritance was also
broken.

Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

.gitlab-ci.yml

@@ -106,6 +106,7 @@ pages:
 
 codestyle_job:
   stage: sanity_checks
+  extends: .gitlab_native_build_job
   needs:
     - job: x86_64-opensuse-leap-15-container
       optional: true