Filter Natural Name Warning

This hides the warning like when writing the output file:
`NaturalNameWarning: object name is not a valid Python identifier:
'lat_50.75_lon_9.25'`

attrici/detrend.py

@@ -3,6 +3,7 @@
 import importlib.metadata
 import pickle
 import sys
+import warnings
 from dataclasses import dataclass
 from datetime import date
 from pathlib import Path
@@ -13,12 +14,16 @@
 import xarray as xr
 from func_timeout import FunctionTimedOut, func_timeout
 from loguru import logger
+from tables import NaturalNameWarning
 
 import attrici
 from attrici import variables
 from attrici.estimation.model_pymc3 import ModelPymc3
 from attrici.util import timeit
 
+warnings.filterwarnings("ignore", category=NaturalNameWarning)
+
+
 MODEL_FOR_VAR = {
     "tas": variables.Tas,
     "tasrange": variables.Tasrange,