[Feature] specify model in config.yaml (#15798)

Signed-off-by: weizeng <weizeng@roblox.com>

tests/conftest.py

@@ -1117,3 +1117,15 @@ def pytest_collection_modifyitems(config, items):
     for item in items:
         if "optional" in item.keywords:
             item.add_marker(skip_optional)
+
+
+@pytest.fixture(scope="session")
+def cli_config_file():
+    """Return the path to the CLI config file."""
+    return os.path.join(_TEST_DIR, "config", "test_config.yaml")
+
+
+@pytest.fixture(scope="session")
+def cli_config_file_with_model():
+    """Return the path to the CLI config file with model."""
+    return os.path.join(_TEST_DIR, "config", "test_config_with_model.yaml")