fix: allow netcdf forcing

[aaraney]

closes #134

Add support for forcing files without patterns (e.g. netcdf).

[hellkite500]

Did you happen to run a test of this with a netcdf realization and forcing file? I had suspected (and I'm still not 💯 convinced) that some additional changes would be needed to handle NetCDFProvider in config. A quick look though implies that maybe that has been supported in the config generation/validation for a while? Maybe this was a lot simpler than I had originally thought 🥳

[aaraney]

I had @ajkhattak run a test to verify that it worked. Still need to test it out for myself.

Aside, I would really like to prioritize getting integration tests setup in CI so this could just become a test case.

[ajkhattak]

I think I can run a quick test to check if it works with both .nc and .csv formats, if that would help.

[aaraney]

@ajkhattak, yeah that would be great. Thanks for offering!

[aaraney]

@ajkhattak, tested and was able to run the model