Access a value by position, use iloc. (#2448)

* "In a future version, integer keys will always be treated as labels (consistent with DataFrame behavior)"

* "In a future version, integer keys will always be treated as labels (consistent with DataFrame behavior)"

---------

Co-authored-by: madtoinou <32447896+madtoinou@users.noreply.github.com>

darts/tests/test_timeseries_static_covariates.py

@@ -647,9 +647,9 @@ def test_ts_methods_with_static_covariates(self):
         static_covs = pd.Series([0, 1], index=["st1", "st2"]).astype(int)
         ts = ts.with_static_covariates(static_covs)
 
-        assert ts.static_covariates.dtypes[0] == "float64"
+        assert ts.static_covariates.dtypes.iloc[0] == "float64"
         ts = ts.astype("float32")
-        assert ts.static_covariates.dtypes[0] == "float32"
+        assert ts.static_covariates.dtypes.iloc[0] == "float32"
 
         ts_stoch = ts.from_times_and_values(
             times=ts.time_index,