refactor: standardize string quotes and improve code readability

Author: wxg0103

apps/application/flow/step_node/tool_lib_node/impl/base_tool_lib_node.py

@@ -124,6 +124,8 @@ def valid_function(tool_lib, workspace_id, user_id=None):
         raise Exception(_("Tool does not exist"))
     if not tool_lib.is_active:
         raise Exception(_("Tool is not active"))
+    if tool_lib.workspace_id == "None":
+        return
     validate_authorized_tool_ids([str(tool_lib.id)], workspace_id, user_id)