#18113: Objects associated to a curses.panel object with set_userptr() were leaked.

Reported by Atsuo Ishimoto.
diff --git a/Misc/NEWS b/Misc/NEWS
index 1479f84..efcd20a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -40,6 +40,9 @@
   the default for linking if LDSHARED is not also overriden.  This restores
   Distutils behavior introduced in 2.7.3 and inadvertently dropped in 2.7.4.
 
+- Issue #18113: Fixed a refcount leak in the curses.panel module's
+  set_userptr() method.  Reported by Atsuo Ishimoto.
+
 Build
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