Remove unnecessary date from copyright notice.

Author: kevinbackhouse

NOTICE

@@ -1,11 +1,11 @@
 Seclab Taskflow Agent
-Copyright 2025 GitHub
+Copyright GitHub, Inc.
 
 This product includes software developed at GitHub (https://github.com) released under the terms
 of the MIT license (https://github.com/GitHubSecurityLab/seclab-taskflow-agent/blob/main/LICENSE)
-Copyright (c) 2025 GitHub
+Copyright GitHub, Inc.
 
 The Initial Developer of some parts of the framework, which are copied from, derived from, or
 inspired by jsonrpyc (https://github.com/riga/jsonrpyc) under the terms of the BSD 3-clause
 license (https://github.com/riga/jsonrpyc/blob/master/LICENSE) is Marcel Rieger
-Copyright (c) 2016-2025, Marcel Rieger
+Copyright 2016-2025, Marcel Rieger