refactor(test): ensure pytest turns warnings into errors

[hassec]

Adds

filterwarnings = [
  "error",
  "ignore:numpy.ndarray size changed, may indicate binary incompatibility. Expected 16 from C header, got 96 from PyObject"
]

to our pyproject.toml.

The first is to turn all warnings into errors.
Line 2 is to ignore the numpy compatibility warnings that netcdf4 generates.

[tbody-cfs]

Nice!

ValueError: The following units are not recognized:
dilution_change_from_core_rad: ducks
edge_impurity_concentration_in_core: chickens