v1.12.1

What's Changed

• Update the CHANGELOG with missing entries by @Omar-V2 in https://github.com/xai-org/xai-sdk-python/pull/135
• Add grok-4.3 to ChatModel by @shawnthapa in https://github.com/xai-org/xai-sdk-python/pull/137
• Bump version from 1.12.0 to 1.12.1 by @shawnthapa in https://github.com/xai-org/xai-sdk-python/pull/138

Full Changelog: https://github.com/xai-org/xai-sdk-python/compare/v1.12.0...v1.12.1