Deal with deprecated pkg_resources API

[brews]

Doing anything with dscim spits out a

src/dscim/__init__.py:11
  /Users/username/Projects/dscim/src/dscim/__init__.py:11: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
    import pkg_resources

because we're using pkg_resource in src/dscim/__init__.py and we're building with setuptools to build our package.

Need to rework this. There is a pretty good chance that this is setting __version__ to "999" because of the way it's coded.

[brews]

I ran into a similar problem updating parameterize_jobs, if we use hatchling and hatch-vcs to build the package instead of setuptools we can do something like this ClimateImpactLab/parameterize_jobs#131

This solves the problem because it keeps a __version__ attr and as far as I can tell this pkg_resources package is only used to get the package version.

The only alternative I know of is trying to import different packages that can get this version information -- and there are a couple of different packages that are all available or not available in different situations. I think xarray and textualize are two packages that opted for this solution. Choose your poison. I feel like the above solution we did for parameterize_jobs is the simplest. This is similar to how black solved the problem.