fix bug: update successors

src/planbee/scheduler/task_batch_processor.py

@@ -12,16 +12,14 @@ class TaskBatchProcessor:
 
     def __init__(self, task_graph: nx.DiGraph, task_dict: dict[str, Task]):
         self.task_graph = task_graph
-        self.task_dict = task_dict
+        self.task_dict = deepcopy(task_dict)
 
     def split_tasks_into_batches(self) -> dict[str, Task]:
         """
         This function performs splitting of tasks into batches if necessary and returns
         an updated task dictionary with possibly split tasks. Tasks are split only if
         they have a batch size and the quantity is greater than the batch size.
         """
-        task_dict_copy = deepcopy(self.task_dict)
-
         # get the order of tasks based on their dependencies
         task_order = list(nx.topological_sort(self.task_graph))
 
@@ -39,13 +37,13 @@ def split_tasks_into_batches(self) -> dict[str, Task]:
             self._update_predecessor_successor_relationships(current_task, task_splits)
 
             # remove the current task from the task dictionary
-            del task_dict_copy[task_uid]
+            del self.task_dict[task_uid]
 
             # add the split tasks to the task dictionary
             for split_task in task_splits:
-                task_dict_copy[split_task.uid] = split_task
+                self.task_dict[split_task.uid] = split_task
 
-        return task_dict_copy
+        return self.task_dict
 
     def _update_predecessor_successor_relationships(
         self, task: Task, batches: list[Task]