Fix: do not pass storage_options into aiohttp

[tropicrainforest]

This PR is going to fix the issue with storage_options={"simplecache": ...} that crashing with TypeError and compressed remote files (.grib2.bz2) failing with EOFError.

In [2]: import xarray as xr
   ...: import tempfile
   ...: 
   ...: URL = "https://opendata.dwd.de/weather/nwp/icon/grib/00/t_2m/icon_global_icosahedral_single-level_2026031300_000_T_2M.grib2.bz2"
   ...: 
   ...: with tempfile.TemporaryDirectory() as tmpdir:
   ...:     dset = xr.open_dataset(
   ...:         URL,
   ...:         engine="prism",
   ...:         storage_options={"simplecache": {"cache_storage": tmpdir}},
   ...:     )
   ...:     print(dset)
   ...: 
WARNING:cfgrib.dataset:ecCodes provides no latitudes/longitudes for gridType='unstructured_grid'
<xarray.Dataset> Size: 12MB
Dimensions:            (values: 2949120)
Coordinates:                                                                                                 
    time               datetime64[ns] 8B ...
    step               timedelta64[ns] 8B ...
    heightAboveGround  float64 8B ...
    valid_time         datetime64[ns] 8B ...
Dimensions without coordinates: values
Data variables:
    t2m                (values) float32 12MB ...
Attributes:
    GRIB_edition:            2
    GRIB_centre:             edzw
    GRIB_centreDescription:  Offenbach
    GRIB_subCentre:          255
    Conventions:             CF-1.7
    institution:             Offenbach
    history:                 2026-03-13T19:06 GRIB to CDM+CF via cfgrib-0.9.1...