Support `copy.replace` from 3.13

There are two things that we need to do:
1. Add 3.13 to CI
2. Add `__replace__` magic method https://docs.python.org/3.13/library/copy.html#object.__replace__ to `Container` base class, so we can support https://docs.python.org/3.13/library/copy.html#copy.replace

Start by locating the Container base class and the repository's CI configuration, then read Python 3.13's copy.replace and object.__replace__ documentation linked in the issue. Done means CI includes Python 3.13 and Container supports __replace__ so copy.replace works with it.

索引モデルが issue の本文から書いたものです。