Merge pull request #302 from c-bata/hotfix-lightgbm

[hotfix] Add the version constraint on lightgbm

Author: not522

.github/workflows/lightgbm.yml

@@ -32,6 +32,9 @@ jobs:
         python -c 'import optuna_integration'
 
         pip install -r lightgbm/requirements.txt
+
+        # TODO(c-bata): Remove the version constraint on LightGBM once the issue is fixed.
+        pip install "lightgbm<=4.5.0"
     - name: Run LightGBM examples
       run: |
         python lightgbm/lightgbm_simple.py