v1.11.2: Improve from_openai method.

What's Changed

• Add test and docstring to get_validator by @juliendenize in https://github.com/mistralai/mistral-common/pull/219
• Improve from openai methods by @juliendenize in https://github.com/mistralai/mistral-common/pull/221
• Version 1.11.2 by @juliendenize in https://github.com/mistralai/mistral-common/pull/222

Full Changelog: https://github.com/mistralai/mistral-common/compare/v1.11.1...v1.11.2