Update license copyright year(s) (#479)

Co-authored-by: github-actions <github-actions@github.com>

Author: paddyroddy

LICENCE.txt

@@ -1,6 +1,6 @@
 BSD 3-Clause Licence
 
-Copyright (c) 2017-2025, Patrick J. Roddy
+Copyright (c) 2017-2026, Patrick J. Roddy
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without