test(responses): repair two tests broken by the gpt-5 temperature gate

PR #38593 stopped forwarding temperature to reasoning models, which left
test_extra_body_merges_with_request_data raising UnsupportedParamsError
and test_bad_request_bad_param_error no longer getting a rejection from
OpenAI because drop_params now eats the param. Both repairs are the same
hunks PR #38739 carries, so the branches merge clean in either order

tests/llm_responses_api_testing/test_openai_responses_api.py

@@ -1818,6 +1818,7 @@ async def test_extra_body_merges_with_request_data(extra_body_mock_response_data
             input="Test",
             temperature=0.7,
             max_output_tokens=20,
+            reasoning={"effort": "none"},
             extra_body={
                 "custom_field": "custom_value",
             },

tests/openai_endpoints_tests/test_e2e_openai_responses_api.py

@@ -115,9 +115,9 @@ def test_bad_request_error():
 def test_bad_request_bad_param_error():
     client = get_test_client()
     with pytest.raises(BadRequestError):
-        # Trigger error with invalid model name
+        # needs a non-reasoning model so drop_params keeps temperature for OpenAI to reject
         client.responses.create(
-            model="gpt-5.5", input="This should fail", temperature=2000
+            model="gpt-4.1-mini", input="This should fail", temperature=2000
         )