Pin pandas to less noisy 2.1.4 (#988)

Addresses part of #984, at least for our dev environment. I'm keeping
#984 open to remind us to unpin it when a new pandera is out.

This also adds [xugrid](https://github.com/Deltares/xugrid) and netCDF4
to our pixi environment. Not as a ribasim dependency, but will need it
to run conversion scripts from #969.