Moved dependency from pydantic to pydantic-settings

[infohash]

BaseSettings have been moved to pydantic-settings package under the same maintainer. As Pyoidc is using BaseSettings only in oic.utils.settings, we can change the dependency without any problem.

[schlenk]

Seems autodoc-pydantic isn't fit for the new v2 api yet either:
mansenfranzen/autodoc_pydantic#146

Your change is okay, so I'm merging this, to have working code.
The docs will hopefully fix themselves once autodoc_pydantic gets updated.

[mansenfranzen]

@infohash @schlenk You can now test the new autodoc_pydantic version supporting pydantic v2 via pip install autodoc_pydantic==2.0.0. The dev docs already showcase v2 support (see here). Migration guide is available here.

Any feedback is more than appreciated. The current autodoc_pydantic version 2.0.0 on pypi remains yanked for one week until final release.

[schlenk]

Thanks for the fix @mansenfranzen . I tried it in a branch (#863) and it seems to fix the issue with the documentation.