unpin pydantic

[joamatab]

Why are these changes needed?

Unpin pydantic

Related issue number

fixes #39161

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[ddelange]

ref #40451

[shrekris-anyscale]

We've merged the changes to make Ray compatible with Pydantic 2.5+. You can start using Pydantic 2.5+ with Ray 2.9, which should be out at the end of December.

These changes should also be in the Ray nightly, so feel free to try them out!