refactor: Remove unused code in large_language_model.py (#5433)

api/tests/integration_tests/model_runtime/openai/test_llm.py

@@ -156,12 +156,6 @@ def test_invoke_chat_model(setup_openai_mock):
     assert isinstance(result, LLMResult)
     assert len(result.message.content) > 0
 
-    for chunk in model._llm_result_to_stream(result):
-        assert isinstance(chunk, LLMResultChunk)
-        assert isinstance(chunk.delta, LLMResultChunkDelta)
-        assert isinstance(chunk.delta.message, AssistantPromptMessage)
-        assert len(chunk.delta.message.content) > 0 if chunk.delta.finish_reason is None else True
-
 @pytest.mark.parametrize('setup_openai_mock', [['chat']], indirect=True)
 def test_invoke_chat_model_with_vision(setup_openai_mock):
     model = OpenAILargeLanguageModel()