Merge pull request optuna#5373 from eukaryo/backport-5366

[Backport] Fix `average_is_best` implementation in `WilcoxonPruner`

Merge pull request optuna#5333 from HideakiImamura/backport-v3.6.0

[Backport] Revert PR optuna#5269

Merge pull request optuna#5144 from nabenabe0928/release-v3.5.0

Bump up version number to 3.5.0

Merge pull request optuna#5031 from not522/bump-to-v3.4.0

Bump the version up to v3.4.0

Merge pull request optuna#4860 from c-bata/bump-to-v3.3.0

Bump the version up to v3.3.0

Merge pull request optuna#4711 from c-bata/bump-to-v3.2.0

Bump up version number to 3.2.0

Merge pull request optuna#4581 from contramundum53/backport-4443

[Backport] Fix CMA-ES Sampler

Merge pull request optuna#4494 from c-bata/fix-scipy-dependency-metadata

Fix a project metadata for scipy version constraint

Merge pull request optuna#4346 from HideakiImamura/bump-version-numbe…

…r-3.1.0

Bump up version number to 3.1.0

update optuna version (optuna#4262)