Fix the problem of Workflow terminates after parallel tasks execution, merge node not triggered (#12498)

Co-authored-by: Novice Lee <novicelee@NoviPro.local>

api/core/workflow/graph_engine/entities/graph.py

@@ -590,6 +590,8 @@ class Graph(BaseModel):
                             start_node_id=node_id,
                             routes_node_ids=routes_node_ids,
                         )
+                        # Exclude conditional branch nodes
+                        and all(edge.run_condition is None for edge in reverse_edge_mapping.get(node_id, []))
                     ):
                         if node_id not in merge_branch_node_ids:
                             merge_branch_node_ids[node_id] = []