Revert "fix:deepseek tool call not working correctly" (#12463)

api/core/model_runtime/model_providers/openai_api_compatible/llm/llm.py

                 for tool in tools:
                     formatted_tools.append(helper.dump_model(PromptMessageFunction(function=tool)))
 
-                if prompt_messages[-1].role.value == "tool":
-                    data["tools"] = None
-                else:
-                    data["tools"] = formatted_tools
+                data["tools"] = formatted_tools
 
         if stop:
             data["stop"] = stop