[Python] allow pydantic < 3.0 in deps

[FyZzyss]

Please, update pydantic version pin in pyproject.toml to < 3.0 instead <2.5.0. Pydantic already has 2.5.2 tag.

I start big migration in my company from Pydantic 1.x to 2.5.2 and it's blocked;(

[Mark Phelps]

@FyZzyss I'm a python noob, will this work: https://github.com/flipt-io/flipt-client-sdks/pull/36/files ?

[FyZzyss]

@markphelps Wow! Thank you for such quick response.
Yes, this will work

[FyZzyss]

@markphelps Will you create a new tag/release for https://github.com/flipt-io/flipt-python with updated deps? For quick installation from pypi. I'll be very grateful