Update copyright year to 2026

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: dblock

LICENSE.md

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2013-2021 Daniel Doubrovkine.
+Copyright (c) 2013-2026 Daniel Doubrovkine.
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

README.md

@@ -357,7 +357,7 @@ You're encouraged to contribute to ruby-enum. See [CONTRIBUTING](CONTRIBUTING.md
 
 ## Copyright and License
 
-Copyright (c) 2013-2021, Daniel Doubrovkine and [Contributors](CHANGELOG.md).
+Copyright (c) 2013-2026, Daniel Doubrovkine and [Contributors](CHANGELOG.md).
 
 This project is licensed under the [MIT License](LICENSE.md).