Add license information to files for matrix-dynamic-dns

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

roles/custom/matrix-dynamic-dns/defaults/main.yml

@@ -1,3 +1,13 @@
+# SPDX-FileCopyrightText: 2020 - 2025 Slavi Pantaleev
+# SPDX-FileCopyrightText: 2020 Scott Crossen
+# SPDX-FileCopyrightText: 2021 - 2022 MDAD project contributors
+# SPDX-FileCopyrightText: 2021 Ahmad Haghighi
+# SPDX-FileCopyrightText: 2022 Marko Weltzer
+# SPDX-FileCopyrightText: 2022 Nikita Chernyi
+# SPDX-FileCopyrightText: 2023 Samuel Meenzen
+#
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
 ---
 # Project source code URL: https://github.com/linuxserver/docker-ddclient