Fixed #36855, Refs #27222 -- Mentioned multiple invocations of Field.pre_save() in 6.0 release notes.

Co-authored-by: Jacob Walls <jacobtylerwalls@gmail.com>

Author: kundan223

docs/releases/6.0.txt

@@ -481,6 +481,12 @@ Miscellaneous
 * The minimum supported version of ``asgiref`` is increased from 3.8.1 to
   3.9.1.
 
+.. currentmodule:: django.db.models
+
+* :meth:`Field.pre_save` may now be called more than once when saving model
+  instances, so custom implementations should be idempotent and free of side
+  effects.
+
 .. _deprecated-features-6.0:
 
 Features deprecated in 6.0