Better processing tests (#46374)
* special tokens always present
* fix
* Update tests/test_processing_common.py
Co-authored-by: Pablo Montalvo <39954772+molbap@users.noreply.github.com>
* revert
* fix
* skip
* ci still flaky, retrigger
---------
Co-authored-by: Pablo Montalvo <39954772+molbap@users.noreply.github.com>
