Fix issue where band array of strs caused Raster(xdata) to fail

np.allclose was used to compare the band array to [1, ..., N] but this
failed when the band array had dtype('O'). This comparison was not
really necessary anyway so now the band array is simply overwritten.

raster_tools/raster.py

@@ -586,9 +586,8 @@ def normalize_xarray_data(xdata):
         xdata = xdata.rename(name_mapping)
     xdata = xdata.transpose("band", "y", "x", transpose_coords=True)
 
-    band_coords = np.arange(1, len(xdata.band) + 1)
-    if not np.allclose(xdata.band.to_numpy(), band_coords):
-        xdata["band"] = band_coords
+    # Make sure that the band dim is the series [1, 2, ..., N].
+    xdata["band"] = np.arange(1, len(xdata.band) + 1)
     if any(dim not in xdata.coords for dim in xdata.dims):
         raise ValueError(
             "Invalid coordinates on xarray.DataArray object:\n{xdata!r}"

tests/test_raster.py

@@ -434,6 +434,14 @@ def test_raster_from_dataarray(xdata):
     assert np.allclose(raster._ds.y, xdata[yc])
 
 
+def test_raster_from_dataarray_str_band(xdem_small):
+    xdem_small["band"] = ["one"]
+    raster = Raster(xdem_small)
+    assert np.allclose(raster.band, np.array([1]))
+    assert np.allclose(raster.xdata.band.to_numpy(), np.array([1]))
+    assert raster.xdata.band.to_numpy().dtype == I64
+
+
 @pytest.mark.parametrize(
     "ds",
     [