doc: remove For ... comments

We don't add or maintain these, and they are of little value, as
well as having the effect of polluting diffs.

They are also wrong, i.e DEFAULT_SCRIPTCHECK_THREADS is not in
validation.h.

src/util/fs_helpers.cpp

@@ -1,5 +1,5 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2023 The Bitcoin Core developers
+// Copyright (c) 2009-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.
 
@@ -37,8 +37,8 @@
 #include <sys/resource.h>
 #include <unistd.h>
 #else
-#include <io.h> /* For _get_osfhandle, _chsize */
-#include <shlobj.h> /* For SHGetSpecialFolderPathW */
+#include <io.h>
+#include <shlobj.h>
 #endif // WIN32
 
 /** Mutex to protect dir_locks. */