Fix SciPy warnings and errors (#678)

tests/test_coreg/test_biascorr.py

@@ -321,7 +321,7 @@ def test_biascorr__bin_2d(self, fit_args, bin_sizes, bin_statistic) -> None:
             scipy.optimize.curve_fit,
         ],
     )  # type: ignore
-    @pytest.mark.parametrize("bin_sizes", (10, {"elevation": np.arange(0, 1000, 100)}))  # type: ignore
+    @pytest.mark.parametrize("bin_sizes", (100, {"elevation": np.arange(0, 1000, 100)}))  # type: ignore
     @pytest.mark.parametrize("bin_statistic", [np.median, np.nanmean])  # type: ignore
     def test_biascorr__bin_and_fit_1d(self, fit_args, fit_func, fit_optimizer, bin_sizes, bin_statistic) -> None:
         """Test the _fit_func and apply_func methods of BiasCorr for the bin_and_fit case (called by all subclasses)."""
@@ -377,6 +377,10 @@ def test_biascorr__bin_and_fit_1d(self, fit_args, fit_func, fit_optimizer, bin_s
     def test_biascorr__bin_and_fit_2d(self, fit_args, fit_func, fit_optimizer, bin_sizes, bin_statistic) -> None:
         """Test the _fit_func and apply_func methods of BiasCorr for the bin_and_fit case (called by all subclasses)."""
 
+        # Curve fit can be unhappy in certain circumstances for numerical estimation of covariance
+        # We don't care for this test
+        warnings.filterwarnings("ignore", message="Covariance of the parameters could not be estimated*")
+
         # Create a bias correction object
         bcorr = biascorr.BiasCorr(
             fit_or_bin="bin_and_fit",