Tests with Python 3.12

[toshihikoyanase]

Motivation

Python 3.12 is available, but optuna-fast-fanova has not yet been tested with it in CI.

Description

We should add 3.12 to the python-version matrix in the CI configuration.

optuna-fast-fanova/.github/workflows/python-tests.yml

Line 31 in de9d44f

python-version: ['3.7', '3.8', '3.9', '3.10', '3.11']

Additionally, if the CI fails with Python 3.12, we may need to update the codebase to resolve compatibility issues.