Pin dependencies and move to uv #19
Description
Description of feature
Right now the dependencies are not pinned, which will mean things will break in the future. We should add upper version limits to all dependencies, which tools like uv do automatically. uv is the default in the new cookiecutter and can be used by hatch as well.
It would also be good to follow the packaging advice in https://www.pyopensci.org/python-package-guide/ and https://github.com/scverse/cookiecutter-scverse.