[Bug]: land sea mask incorrectly generated for non-regular lat/lon grid

[lee1043]

Reported by @acordonez

What happened?

Input data:

Generated land sea mask:

What did you expect to happen? Are there are possible answers you came across?

Minimal Complete Verifiable Example (MVCE)

f_nt_n = "/home/ordonez4/seaice/data/icecon_ssmi_nt_n_edited.nc"

obs = xc.open_dataset(f_nt_n)

if 'history' in obs.attrs:
    del obs.attrs['history']  # Just because it is too long on screen..!

obs["ice_con"] = obs["ice_con"] * 0.01
obs["area"] = obs["area"] * 1e-6
mask_pmp = create_land_sea_mask(obs)
mask_pmp.plot()

Relevant log output

No response

Anything else we need to know?

No response

Environment

pmp v3.1.2