Update README.md copyright.

Closes signalapp#14060

Author: mynameistito

README.md

@@ -54,7 +54,7 @@ The form and manner of this distribution makes it eligible for export under the
 
 ## License
 
-Copyright 2013-2024 Signal Messenger, LLC
+Copyright 2013-2025 Signal Messenger, LLC
 
 Licensed under the GNU AGPLv3: https://www.gnu.org/licenses/agpl-3.0.html