Serialization disagrees with typing for recent Python versions

Newer Python versions (I think 3.12 and up) are seriously overhauling the typing system.
(Specifically interactions between type hints, types.GenericAlias and inspect)

This causes the existing serialization module to break, rendering Psiflow unusable.
There is no immediate problem for now.
However, some overhauling will be required when we eventually want to upgrade.