fix: pin marshmallow dependency

[Panaetius]

No description provided.

[sloria]

👋 marshmallow maintainer here. was searching for usages of SchemaABC which brought me to this repo. i think you can fix compatibility with marshmallow>=3.24.0 by replacing the import of SchemaABC here:

calamus/calamus/fields.py

Line 28 in c59d6fe

from marshmallow.base import SchemaABC

with

from marshmallow.schema import Schema

and replacing SchemaABC with Schema in the code

[Panaetius]

Thanks for the heads up!