Issue with test pytest tests/io/test_read_aeronet_invv3.py

[thorbjoernl]

Describe the bug
Please provide a clear and concise description of what the bug is.

• Pyaerocom version: 0.26.dev0
• Computing platform: NA
• Configuration file (if applicable): NA
• Error message (if applicable):

Exception has occurred: KeyError       (note: full exception trace is shown but execution is paused at: __getitem__)
AttributeError("'StationData' object has no attribute 'abs500aer'")
  File "/home/thlun8736/Documents/work/pyaerocom/pyaerocom/_lowlevel_helpers.py", line 251, in __getitem__
    return getattr(self, key)
AttributeError: 'StationData' object has no attribute 'abs500aer'

To Reproduce
Steps to reproduce the behavior:

1. Checkout main-dev
2. pytest tests/io/test_read_aeronet_invv3.py

Expected behavior
No test error.

Screenshots
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Additional context
Add any other context about the problem here.

The file the test attempts to read is /lustre/storeB/project/aerocom/aerocom1/AEROCOM_OBSDATA/Aeronet.Inv.V3L2.0.daily/renamed/19930101_20241207_Berlin_FUB.all