Issue #25155: document the bugfix in Misc/NEWS

Oops, I forgot to document my change.
diff --git a/Misc/NEWS b/Misc/NEWS
index 02917a1..1910529 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -14,6 +14,10 @@
 Library
 -------
 
+- Issue #25155: Fix datetime.datetime.now() and datetime.datetime.utcnow() on
+  Windows to support date after year 2038. It was a regression introduced in
+  Python 3.5.0.
+
 - Issue #25108: Omitted internal frames in traceback functions print_stack(),
   format_stack(), and extract_stack() called without arguments.