community/py3-itsdangerous: upgrade to 2.0.1 and modernize

Follow-up to !21490 (merged) community/py3-itsdangerous: upgrade to 2.0.0 was not applied

fixes aarch64 builder build-edge-aarch64/testing/py3-flask-migrate/py3-flask-migrate-3.0.0-r0.log

https://pypi.org/project/itsdangerous/2.0.1/#history