Update tests/templates/kuttl/versioning/30-install-airflow-cluster.yaml.j2

Co-authored-by: Andrew Kenworthy <1712947+adwk67@users.noreply.github.com>

Author: sbernauer

tests/templates/kuttl/versioning/30-install-airflow-cluster.yaml.j2

@@ -63,7 +63,7 @@ spec:
       - repo: https://github.com/stackable-airflow/dags
         # v1alpha1 field which should be converted to an enum
         # N.B. only works for the existing v1 field
-        credentialsSecretName: airflow-git-credentials
+        credentialsSecret: airflow-git-credentials
         gitFolder: "mount-dags-gitsync/dags_airflow3"
         wait: 5s
   webservers: