Update how pydantic models load configurations to comply with pydantic 2

[banagale]

Summary

Fixes #678

• Updates method of setting pydantic model configuration to 2.0 standard.

List of files changed and why

crawl4ai.models.py - Had two models using old style of pydantic configuration

How Has This Been Tested?

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added/updated unit tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[banagale]

I'm seeing "Merge is not an allowed merge method in this repository." on the new and improved merge experience here. Switching to classic, it seems fine.

If this merge is blocked due to something on my end, please lmk.

[banagale]

This is a fairly minor fix, so I have not written tests. Please let me know if there are additional changes needed.