Use dependency-group for "dev" and other non-user-facing dependencies

pyproject.toml specifies two types of dependency sets: "extras" and "groups." The first is specified by [project.optional-dependencies] (this is what we have now), and the second is specified by [dependency-groups]. Extras may be installed with the package-name[extra-name] syntax, while groups are not supposed to be user-facing, are not listed on PyPI, and may be installed with the --group flag.

I propose making "dev" a dependency group in the template and changing CI/setup scripts to use it this way. This will make the extras list cleaner.

https://packaging.python.org/en/latest/specifications/pyproject-toml/#dependencies-optional-dependencies
https://packaging.python.org/en/latest/specifications/dependency-groups/

LSDB at PyPI

首先检查模板的 pyproject.toml，以及用于安装开发依赖项的 CI 和设置脚本。更新模板，使开发依赖项和其他非面向用户的依赖项使用 [dependency-groups]，并确保这些脚本使用分组机制；当 extras 列表不再包含开发依赖项，并且生成项目的设置仍然正常运行时，即表示完成。