Drop support for Pydantic v1

[leandrodamascena]

Hey @monim67 I think it's time to drop support for Pydantic v1 and avoid errors like this:

plugin.py:16: UserWarning: Core Pydantic V1 functionality isn't compatible with Python 3.14 or greater.
  from pydantic.v1 import ValidationError

Pydantic v2 is 2 yrs old now and very mature, so, I think it's ok you drop.

[monim67]

I have same idea, will take it out soon.