bucket_sum resampler fails due to unexpected fill_value kwarg

[ameraner]

Describe the bug
The bucket_sum resampler fails due to a fill_value argument

satpy/satpy/resample.py

Lines 1067 to 1068 in 233f698

	fill_value = kwargs.pop("fill_value", get_fill_value(dataset))
	new_data = resample(source_area, dataset, destination_area, fill_value=fill_value, **kwargs)

that is then passed as kwarg to pyresample here:

satpy/satpy/resample.py

Lines 916 to 921 in 233f698

	for i in range(data.shape[0]):
	res = self.resampler.get_sum(data[i, :, :], skipna=skipna,
	**kwargs)
	results.append(res)
	else:
	res = self.resampler.get_sum(data, skipna=skipna, **kwargs)

and is then not accepted inside pyresample: https://github.com/pytroll/pyresample/blob/4e18999cb76c3404d0f5ec3df04b3350e56f0612/pyresample/bucket/__init__.py#L205

To Reproduce

path_to_testdata = '/tcenas/scratch/andream/lil2a/'
scn = Scene(filenames=glob(os.path.join(path_to_testdata, '*AF*---*T_0073_0001.nc')), reader='li_l2_nc',
            reader_kwargs={'with_area_definition': False})
scn.load(['flash_accumulation'], upper_right_corner='NE')
# resample 1-d array onto grid
scn_r = scn.resample('mtg_fci_fdss_2km', resampler='bucket_sum')

Expected behavior
Working resampler

Actual results

DEBUG: 2024-05-22 13:32:11 : satpy.resample] Initializing bucket resampler.
/tcenas/home/andream/anaconda3/envs/devenv/lib/python3.11/site-packages/pyproj/crs/crs.py:1293: UserWarning: You will likely lose important projection information when converting to a PROJ string from another format. See: https://proj.org/faq.html#what-is-the-best-format-for-describing-coordinate-reference-systems
  proj = self._crs.to_proj4(version=version)
[INFO: 2024-05-22 13:32:11 : pyresample.bucket] Determine bucket resampling indices
[DEBUG: 2024-05-22 13:32:11 : satpy.resample] Resampling DataID(name='flash_accumulation', modifiers=())
Traceback (most recent call last):
  File "/tcenas/proj/optcalimg/andream/pycharm_install/pycharm-2022.3.2/plugins/python/helpers/pydev/pydevd.py", line 1496, in _exec
    pydev_imports.execfile(file, globals, locals)  # execute the script
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tcenas/proj/optcalimg/andream/pycharm_install/pycharm-2022.3.2/plugins/python/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "/tcenas/home/andream/PycharmProjects/dev_src/dev_src/li_data/plot_li_data.py", line 31, in <module>
    scn_r = scn.resample('mtg_fci_fdss_2km', resampler='bucket_sum')
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tcenas/home/andream/code/satpy_latest/satpy/satpy/scene.py", line 977, in resample
    self._resampled_scene(new_scn, destination, resampler=resampler,
  File "/tcenas/home/andream/code/satpy_latest/satpy/satpy/scene.py", line 893, in _resampled_scene
    res = resample_dataset(dataset, destination_area, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tcenas/home/andream/code/satpy_latest/satpy/satpy/resample.py", line 1068, in resample_dataset
    new_data = resample(source_area, dataset, destination_area, fill_value=fill_value, **kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tcenas/home/andream/code/satpy_latest/satpy/satpy/resample.py", line 1031, in resample
    res = resampler_instance.resample(data, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tcenas/home/andream/code/satpy_latest/satpy/satpy/resample.py", line 815, in resample
    result = self.compute(data_arr, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/tcenas/home/andream/code/satpy_latest/satpy/satpy/resample.py", line 921, in compute
    res = self.resampler.get_sum(data, skipna=skipna, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: BucketResampler.get_sum() got an unexpected keyword argument 'fill_value'

Additional Information
There are two solutions:

1. we handle this in satpy and make sure not to pass the fill_value argument
2. we handle this in pyresample and add support for fill_value, as already done for the other bucket resamplers.

I would likely go for the second option as it is a useful feature for pyresample and keeps a consistent interface in satpy.