Fix comments.

libclide-macros/src/lib.rs

@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2026, Shaun Reed <shaunrd0@gmail.com>
+//
+// SPDX-License-Identifier: GNU General Public License v3.0 or later
+
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::{ItemStruct, parse_macro_input};