[Test Fix]Fix test nit, there is no public is_live method provided. (m…

…icrosoft#3298)

# Description

Fix test nit, there is no public is_live method provided.

# All Promptflow Contribution checklist:
- [ ] **The pull request does not introduce [breaking changes].**
- [ ] **CHANGELOG is updated for new features, bug fixes or other
significant changes.**
- [ ] **I have read the [contribution guidelines](../CONTRIBUTING.md).**
- [ ] **Create an issue and link to the pull request to get dedicated
review from promptflow team. Learn more: [suggested
workflow](../CONTRIBUTING.md#suggested-workflow).**

## General Guidelines and Best Practices
- [ ] Title of the pull request is clear and informative.
- [ ] There are a small number of commits, each of which have an
informative message. This means that previously merged commits do not
appear in the history of the PR. For more information on cleaning up the
commits in your PR, [see this
page](https://github.com/Azure/azure-powershell/blob/master/documentation/development-docs/cleaning-up-commits.md).

### Testing Guidelines
- [ ] Pull request includes test coverage for the included changes.

src/promptflow-devkit/tests/sdk_cli_test/e2etests/test_flow_serve.py

@@ -12,7 +12,6 @@
 from promptflow._utils.multimedia_utils import OpenaiVisionMultimediaProcessor
 from promptflow.core._serving.constants import FEEDBACK_TRACE_FIELD_NAME
 from promptflow.core._serving.utils import load_feedback_swagger
-from promptflow.recording.record_mode import is_live
 from promptflow.tracing._operation_context import OperationContext
 
 
@@ -506,7 +505,7 @@ def test_prompty_serving_api(prompty_serving_client):
 
 @pytest.mark.usefixtures("recording_injection", "setup_local_connection")
 @pytest.mark.e2etest
-@pytest.mark.skipif(not is_live(), reason="llm request involved but no recording found")
+@pytest.mark.skipif(not pytest.is_live, reason="llm request involved but no recording found")
 def test_prompty_serving_api_live(prompty_serving_client):
     response = prompty_serving_client.post(
         "/score", data=json.dumps({"firstName": "first", "lastName": "last", "question": "hello"})