Update copyright notices to 2025

This updates all the copyright notices to be relevant with the current
dates, for the code where this matters.  This should have been done much
earlier in the year, but better than never in preparation for the
upcoming release.  The notices are updated for all the files down to the
PG18 branch, as this branch has not been released yet.

On back-branches, the copyright dates are only updated for the docs and
the COPYRIGHT file, where they mostly matter.

Author: michaelpq

COPYRIGHT

@@ -1,4 +1,4 @@
-Copyright (c) 2012-2023, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+Copyright (c) 2012-2025, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without

COPYRIGHT.postgresql

@@ -3,7 +3,7 @@ PostgreSQL Database Management System.
 (formerly known as Postgres, then as Postgres95)
 Copyright holders of those files are following organizations:
 
-Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 
 Portions Copyright (c) 1994, The Regents of the University of California
 

docs/conf.py

@@ -7,7 +7,7 @@
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
 
 project = 'pg_hint_plan'
-copyright = '2012-2023, NIPPON TELEGRAPH AND TELEPHONE CORPORATION'
+copyright = '2012-2025, NIPPON TELEGRAPH AND TELEPHONE CORPORATION'
 author = 'NIPPON TELEGRAPH AND TELEPHONE CORPORATION'
 
 # -- General configuration ---------------------------------------------------