Remove TensorFlowProningHook's Python 3.12 support

Author: kAIto47802

.github/workflows/checks-and-tests.yml

@@ -218,6 +218,7 @@ jobs:
     with:
       integration_name: 'tensorflow'
       deprecated: false
+      python_matrix: "['3.8', '3.9', '3.10', '3.11']"
 
   tfkeras:
     if: needs.changes.outputs.tfkeras == 'true'

optuna_integration/tensorflow/tensorflow.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import optuna
+from optuna._deprecated import deprecated_class
 
 from optuna_integration._imports import try_import
 
@@ -15,6 +16,15 @@
     SessionRunHook = object  # NOQA
 
 
+@deprecated_class(
+    "4.0.0",
+    "5.0.0",
+    text=(
+        "Use :class:`~optuna_integration.KerasPruningCallback`, "
+        "since [TensorFlow recommends migrating from Estimator to Kras APIs]"
+        "(https://www.tensorflow.org/guide/migrate/migrating_estimator)."
+    ),
+)
 class TensorFlowPruningHook(SessionRunHook):
     """TensorFlow SessionRunHook to prune unpromising trials.