using uv for dev setup, build, publish

[shimizukawa]

This pull request includes several significant changes to the build and testing workflows, dependency management, and documentation. The most important changes are detailed below:

Workflow and Build Process Updates:

• Renamed workflow from test.yml to ci.yml to handle testing, building, and releasing the project. This includes steps for setting up Python environments, running tests with Tox, building the package, and publishing releases to PyPI and GitHub.

Dependency Management:

• Updated .devcontainer/on_create_command.sh to use the uv tool for installing dependencies and tools such as ruff and tox.
• Modified pyproject.toml to include a new [dependency-groups] section for development dependencies and updated the build system requirements.

Documentation Updates:

• Updated checklist.rst to reflect the new release procedure, including creating GitHub releases and updating the PyPI page.
• Updated doc/dev.rst to use uv for setting up the development environment.

Configuration and Metadata:

• Removed setup.cfg as part of the transition to using pyproject.toml for configuration.
• Updated sphinx_intl/__init__.py to dynamically fetch the package version using importlib.metadata.

These changes streamline the development and release processes, improve dependency management, and update the project documentation to reflect the new workflows.