scripted-diff: [doc] Unify stale copyright headers

-BEGIN VERIFY SCRIPT-

 sed --in-place --regexp-extended \
   's;( 20[0-2][0-9])(-20[0-2][0-9])? The Bitcoin Core developers;\1-present The Bitcoin Core developers;g' \
   $( git grep -l 'The Bitcoin Core developers' -- ':(exclude)COPYING' ':(exclude)src/ipc/libmultiprocess' ':(exclude)src/minisketch' )

-END VERIFY SCRIPT-

src/test/util/validation.cpp

@@ -1,4 +1,4 @@
-// Copyright (c) 2020-2022 The Bitcoin Core developers
+// Copyright (c) 2020-present The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.