Move dependencies from setup.py to project.toml

[cocolato]

Fix the error when run python -m build:

        ********************************************************************************
        The following seems to be defined outside of `pyproject.toml`:

        `optional-dependencies = {'dev': ['flake8>=2.5', 'sphinx-rtd-theme>=0.1.9', 'sphinx>=1.3', 'pytest-reraise', 'pytest<8.2.0,>=6.1.1', 'tornado<7.0,>=4.0; python_version >= "3.12"', 'tornado<6.0,>=4.0; python_version < "3.12"'], 'tornado': ['tornado<7.0,>=4.0; python_version >= "3.12"', 'tornado<6.0,>=4.0; python_version < "3.12"']}`

        According to the spec (see the link below), however, setuptools CANNOT
        consider this value unless `optional-dependencies` is listed as `dynamic`.

        https://packaging.python.org/en/latest/specifications/pyproject-toml/#declaring-project-metadata-the-project-table

        To prevent this problem, you can list `optional-dependencies` under `dynamic` or alternatively
        remove the `[project]` table from your file and rely entirely on other means of
        configuration.
        ********************************************************************************

[cocolato]

@aisk Do you think this implementation makes sense now？

[aisk]

Tornado support will be deprecated, so I think this is ok for me.