``KeyError: 'valid_range'`` when loading AIRS-2-0 data

[schlunma]

The fix for hur of AIRS-2-0 expects the valid_range attribute:

ESMValCore/esmvalcore/cmor/_fixes/obs4mips/airs_2_0.py

Lines 8 to 36 in 0bb7e86

	class Hur(Fix):
	"""Fixes for hur."""
	def fix_metadata(self, cubes):
	"""Fix metadata.
	Convert units from `1` to `%` and remove `valid_range` attribute.
	Parameters
	----------
	cubes: iris.cube.CubeList
	Input cubes.
	Returns
	-------
	iris.cube.CubeList
	Fixed cubes.
	"""
	for cube in cubes:
	# Put information from valid_range into mask and remove the
	# attribute (otherwise this will cause problems after reloading the
	# data with different units)
	valid_range = cube.attributes["valid_range"]
	cube.data = da.ma.masked_outside(cube.core_data(), *valid_range)
	cube.attributes.pop("valid_range", None)
	cube.convert_units("%")
	return cubes

This has been removed in #3072.

This bug has not been published in any release.