Add warning about the fact that the TreeBehavior can not handle concurrent requests (#8114)

and that the user need to implement it's own locking to prevent data corruption
See cakephp/cakephp#17174

Signed-off-by: nook24 <d.ziegler@allgeier-its.com>

Author: nook24

en/orm/behaviors/tree.rst

@@ -18,6 +18,7 @@ The TreeBehavior helps you maintain a hierarchical data structure in the
 database that can be queried without much overhead and helps reconstruct the
 tree data for finding and displaying processes.
 
+
 Requirements
 ============
 
@@ -31,6 +32,16 @@ You can configure the name of those fields should you need to customize them.
 More information on the meaning of the fields and how they are used can be found
 in this article describing the `MPTT logic <https://www.sitepoint.com/hierarchical-data-database-2/>`_
 
+.. warning::
+
+    The TreeBehavior is not safe for concurrent write operations.
+    Simultaneous requests that modify tree-structured data
+    (e.g., insertions, deletions, or moves) can lead to corruption of the
+    ``lft`` and ``rght`` values.
+    
+    To prevent this, a locking mechanism like a
+    `Semaphore <https://www.php.net/manual/en/book.sem.php>`_ should be used.
+
 .. warning::
 
     The TreeBehavior does not support composite primary keys at this point in