fix: comment where mask raster by polygons since the code does not work for some reasons

[JinIgarashi]

I found the below code does not work, and thread will end before finishing geometry_mask process. to be honest, I don't understand why this happens.

I just commented the below code to make sure download_raster function works.

masking raster data by project polygons can be desired in terms of reducing file size, but there is also no impact of computing zonal stats including all pixels. So, commented the code for now.

                    mask_arr = rasterio.features.geometry_mask(
                        geoms,
                        out_shape=(int(source_window.height), int(source_window.width)),
                        transform=src_window_transform,
                        invert=True
                    )
                    data = numpy.where(mask_arr, data, numpy.nan)