eccodes>=2.33.0 breaks loading cubes using iris/iris-grib

[lidiyaKhalil]

ecCodes version 2.33.0 introduced a change to rename indicatorOfUnitOfTimeRange to indicatorOfUnitForForecastTime: https://confluence.ecmwf.int/display/ECC/ecCodes+version+2.33.0+released

This breaks iris-grib as it specifically looks for the old indicatorOfUnitOfTimeRange key within grib files, leading to the error KeyError: 'indicatorOfUnitOfTimeRange not defined in section 4'

Relevant traceback snippet:

File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/__init__.py", line 354, in load_cube
    cubes = _load_collection(uris, constraints, callback).cubes()
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/__init__.py", line 294, in _load_collection
    result = _CubeFilterCollection.from_cubes(cubes, constraints)
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/cube.py", line 97, in from_cubes
    for cube in cubes:
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/__init__.py", line 275, in _generate_cubes
    for cube in iris.io.load_files(part_names, callback, constraints):
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/io/__init__.py", line 222, in load_files
    for cube in handling_format_spec.handler(fnames, callback):
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/fileformats/rules.py", line 433, in load_cubes
    for cube, field in _load_pairs_from_fields_and_filenames(
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/fileformats/rules.py", line 358, in _load_pairs_from_fields_and_filenames
    cube, factories, references = _make_cube(field, converter)
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris/fileformats/rules.py", line 293, in _make_cube
    metadata = converter(field)
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris_grib/_load_convert.py", line 2646, in convert
    grib2_convert(field, metadata)
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris_grib/_load_convert.py", line 2598, in grib2_convert
    product_definition_section(field.sections[4], metadata,
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris_grib/_load_convert.py", line 2453, in product_definition_section
    product_definition_template_0(section, metadata, rt_coord)
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris_grib/_load_convert.py", line 2044, in product_definition_template_0
    time_coords(section, metadata, rt_coord)
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris_grib/_load_convert.py", line 1879, in time_coords
    fp_coord = forecast_period_coord(section['indicatorOfUnitOfTimeRange'],
  File "/opt/conda-lambda/envs/ads310/lib/python3.10/site-packages/iris_grib/message.py", line 436, in __getitem__
    raise KeyError(emsg)

Workaround:
Only use iris-grib with eccodes==2.32.1

[pp-mo]

#504 fixes, hopefully ?