fix: Add support for Pydantic v2.12

[Mantisus]

Description

• Add support pydantic v2.12. This uses a workaround to ensure compatibility with Annotated[..., Field(default_factory=...)] and with type hints.

Issues

• Closes: Updating to Pydantic >3.11.9 causes TypeError on import #1464

[vdusek]

I'm not sure about this workaround - shouldn't we wait for a fix on the Pydantic side instead?

[Mantisus]

shouldn't we wait for a fix on the Pydantic side instead?

I'm not sure that Pydantic will fix this. Since the default value was factually ignored before 2.12, we set it for the type checker.

An example of a discussion in the Pydantic repository - pydantic/pydantic#6713 (comment)

[vdusek]

Thanks for the explanation. The best solution would be if the Pydantic Mypy plugin were able to handle this issue (default_factory vs. standard default field values) - https://docs.pydantic.dev/2.12/integrations/mypy/#enabling-the-plugin. But since it's not the case, this is probably the 2nd best solution, so LGTM.