Update imports in example notebook (#5347)

Author: zhaoqizqwang

v3-examples/ml-ops-examples/v3-hyperparameter-tuning-example/v3-hyperparameter-tuning-pipeline.ipynb

@@ -10,7 +10,7 @@
     "# V3 Imports\n",
     "from sagemaker.train import ModelTrainer\n",
     "from sagemaker.train.configs import Compute, SourceCode, InputData, StoppingCondition\n",
-    "from sagemaker.core.tuner import HyperparameterTuner\n",
+    "from sagemaker.train.tuner import HyperparameterTuner\n",
     "from sagemaker.core.parameter import ContinuousParameter, CategoricalParameter\n",
     "from sagemaker.core.helper.session_helper import get_execution_role\n",
     "from sagemaker.mlops.workflow.steps import TuningStep\n",