Fixed pydantic schema to enable support Pydantic 2.12

[alysenko-nn]

Pull Request Description:

MCT doesn't work correctly with Pydantic 2.12. Root cause is the old-style validator format, which was deprecated in v2.12. Validators were updated to v2 style and work without any issues with the latest (2.12) version

Checklist before requesting a review:

• I set the appropriate labels on the pull request.
• I have added/updated the release note draft (if necessary).
• I have updated the documentation to reflect my changes (if necessary).
• All function and files are well documented.
• All function and classes have type hints.
• There is a licenses in all file.
• The function and variable names are informative.
• I have checked for code duplications.
• I have added new unittest (if necessary).