Support python3.12

[mkdir700]

closes: #392

[mkdir700]

@long2ice Workflow needs to be modified to support running CI on Python 3.12

[Wolfhound905]

I do not agree with just changing to import to v1, a proper transition should be made to the current version on Pydantic.

[mkdir700]

Thank you, I understand this, but this PR is to support Python3.12, not to support Pydanic v2.

Regarding the support for Pydantic V2, I think this should be opened as a separate issue.

[vicchi]

@mkdir700 @Wolfhound905 Support for Python 3.12 will be part of the upcoming 0.3.0 release, see #462

Right now, the package dependencies specify either Pydantic v1 or v2.

The 1.0.0 release will deprecate Pydantic v1 support entirely, see #463

For now I'm going to close this PR in favour of #463, not least because it changes current Pydantic behaviour at the same time as supporting Python 3.12. Feel free to re-open if you disagree.