[LLVM][NFC] fix missing license information

Author: T0b1-iOS

tpde-llvm/test/lli/lit.local.cfg

@@ -1,2 +1,6 @@
+# SPDX-FileCopyrightText: 2025 Contributors to TPDE <https://tpde.org>
+#
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
 if config.system_name != "Linux":
     config.unsupported = True