Fixes: TheAlgorithms#8715 Fix for removing the root node in BST removes the whole tree.

Author: Akash Mandal

data_structures/binary_tree/binary_search_tree.py

@@ -40,7 +40,7 @@ def __reassign_nodes(self, node: Node, new_children: Node | None) -> None:
             else:
                 node.parent.left = new_children
         else:
-            self.root = None
+            self.root = new_children
 
     def is_right(self, node: Node) -> bool:
         if node.parent and node.parent.right: