Update SPDX copyright information in migration guide

Author: mgarciaLKS

migration-guides/GENERIC_BITNAMI_TO_CLOUDPIRATES_KEYCLOAK_MIGRATION_GUIDE.md

@@ -507,5 +507,10 @@ keycloak:
 
 This work is licensed under the [CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/legalcode).
 
+- SPDX-License-Identifier: CC-BY-4.0
+- SPDX-FileCopyrightText: 2025, 2026 Contributors to the Eclipse Foundation
+- SPDX-FileCopyrightText: 2025, 2026 Catena-X Automotive Network e.V.
+- SPDX-FileCopyrightText: 2025, 2026 LKS Next
+
 - SPDX-License-Identifier: CC-BY-4.0
 - SPDX-FileCopyrightText: 2026 Contributors to the Eclipse Foundation