[Test] Fix encoding error in test_pf_flow_test_with_non_english_input…

…_output (#1037)

# Description

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the pull request and link all relevant issues.

# All Promptflow Contribution checklist:
- [ ] **The pull request does not introduce [breaking changes].**
- [ ] **CHANGELOG is updated for new features, bug fixes or other
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## General Guidelines and Best Practices
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- [ ] There are a small number of commits, each of which have an
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### Testing Guidelines
- [ ] Pull request includes test coverage for the included changes.

src/promptflow/tests/sdk_cli_test/e2etests/test_cli.py

@@ -306,13 +306,13 @@ def test_pf_flow_test_with_non_english_input_output(self, capsys):
         stdout, _ = capsys.readouterr()
         output_path = Path(FLOWS_DIR) / "chat_flow" / ".promptflow" / "flow.output.json"
         assert output_path.exists()
-        with open(output_path, "r") as f:
+        with open(output_path, "r", encoding="utf-8") as f:
             outputs = json.load(f)
             assert outputs["answer"] in json.loads(stdout)["answer"]
 
         detail_path = Path(FLOWS_DIR) / "chat_flow" / ".promptflow" / "flow.detail.json"
         assert detail_path.exists()
-        with open(detail_path, "r") as f:
+        with open(detail_path, "r", encoding="utf-8") as f:
             detail = json.load(f)
             assert detail["flow_runs"][0]["inputs"]["question"] == question
             assert detail["flow_runs"][0]["output"]["answer"] == outputs["answer"]