merge NEWS entries into one

Author: gpshead

Misc/NEWS.d/next/Library/2025-12-16-11-55-55.gh-issue-142754.xuCrt3.rst

@@ -1 +1,6 @@
-Remove quadratic behavior in ``xml.minidom`` node ID cache clearing.
+Remove quadratic behavior in ``xml.minidom`` node ID cache clearing.  In order
+to do this without breaking existing users, we also add the *ownerDocument*
+attribute to :mod:`xml.dom.minidom` elements and attributes created by directly
+instantiating the ``Element`` or ``Attr`` class. Note that this way of creating
+nodes is not supported; creator functions like
+:py:meth:`xml.dom.Document.documentElement` should be used instead.