Reading LI L2 point data is not daskified

[gerritholl]

Describe the bug

Loading "radiance" from a LI L2 LGR file gives me the data directly, instead of a dask-aware array.

To Reproduce

# Your code here
from satpy import Scene
from satpy.utils import debug_on; debug_on()
from glob import glob
sc = Scene(filenames=glob("/media/nas/x21308/MTG_test_data/LI/20230712/*LGR*_0042_003*.nc"), reader="li_l2_nc")
sc.load(["radiance"])
print(sc["radiance"])

Expected behavior

I expect that the NetCDF dataset encapsulates a dask array.

Actual results

It encapsulates a regular array, with data values, as follows:

[DEBUG: 2024-06-13 12:47:02 : satpy.readers.yaml_reader] Reading ('/data/gholl/checkouts/satpy/satpy/etc/readers/li_l2_nc.yaml',)                                                                                                    [5/1066]
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.yaml_reader] Assigning to li_l2_nc: ['/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023504_L2PF_IV_20230713065623
_20230713065633_N__T_0042_0039.nc', '/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023408_L2PF_IV_20230713065513_20230713065523_N__T_0042_0032.nc', '/media/n
as/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023432_L2PF_IV_20230713065543_20230713065553_N__T_0042_0035.nc', '/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUME
TSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023424_L2PF_IV_20230713065533_20230713065543_N__T_0042_0034.nc', '/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK
-BODY---NC4E_C_EUMT_20231221023448_L2PF_IV_20230713065603_20230713065613_N__T_0042_0037.nc', '/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023456_L2PF_IV_20
230713065613_20230713065623_N__T_0042_0038.nc', '/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023440_L2PF_IV_20230713065553_20230713065603_N__T_0042_0036.nc
', '/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023352_L2PF_IV_20230713065453_20230713065503_N__T_0042_0030.nc', '/media/nas/x21308/MTG_test_data/LI/202307
12/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023416_L2PF_IV_20230713065523_20230713065533_N__T_0042_0033.nc', '/media/nas/x21308/MTG_test_data/LI/20230712/W_XX-EUMETSAT-Darmstadt,IMG+SAT,MTI1+LI-2-
LGR--FD--CHK-BODY---NC4E_C_EUMT_20231221023400_L2PF_IV_20230713065503_20230713065513_N__T_0042_0031.nc']
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Product type is: 2-LGR
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_base_nc] Adding 10 datasets for 2-LGR input product.
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.li_l2_nc] The current product 2-LGR is not an accumulated product so it will not be regridded.
[DEBUG: 2024-06-13 12:47:02 : satpy.composites.config_loader] Looking for composites config file li.yaml
[DEBUG: 2024-06-13 12:47:02 : satpy.composites.config_loader] Looking for composites config file visir.yaml
[DEBUG: 2024-06-13 12:47:02 : pyorbital.tlefile] Path to the Pyorbital configuration (where e.g. platforms.txt is found): /data/gholl/mambaforge/envs/py312/lib/python3.12/site-packages/pyorbital/etc
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.yaml_reader] No coordinates found for DataID(name='longitude', modifiers=())
[DEBUG: 2024-06-13 12:47:02 : satpy.readers.yaml_reader] No coordinates found for DataID(name='latitude', modifiers=())
<xarray.DataArray 'radiance' (y: 7105)> Size: 28kB
array([ 6. ,  4. , 13. , ...,  8. ,  6.5, 22. ], dtype=float32)
Coordinates:
    crs      object 8B +proj=longlat +ellps=WGS84 +type=crs
Dimensions without coordinates: y
Attributes: (12/18)
    long_name:            Radiance of group
    units:                mW.m-2.sr-1
    use_rescaling:        True
    sensor:               li
    add_offset:           0.0
    name:                 radiance
    ...                   ...
    start_time:           2023-07-13 06:54:53
    end_time:             2023-07-13 06:56:33
    reader:               li_l2_nc
    area:                 Shape: (7105,)\nLons: <xarray.DataArray 'longitude'...
    _satpy_id:            DataID(name='radiance', modifiers=())
    ancillary_variables:  []

Environment Info:

• OS: openSUSE Leap 15.3
• Satpy Version: main branch v0.49.0-55-g367016e29

Additional context

I encapsulated the whole thing in with dask.config.set(scheduler=CustomScheduler(max_computes=0)), expecting it to fail, but it doesn't fail. So it looks like nothing is being computed, it just never is a dask array to begin with.

Reading gridded products, such as AFA, correctly results in a dask array.