CI: fixing the files to be complient with pre-commit hooks

components/esp_modem/examples/linux_modem/main/modem_main.cpp

@@ -1,3 +1,8 @@
+/*
+ * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
 #include <memory>
 #include <cassert>
 #include <unistd.h>
@@ -79,4 +84,4 @@ int main()
 
     usleep(15'000'000);
     esp_netif_destroy(tun_netif);
-}
+}