Service tier support added for priority processing

What's Changed

• feat: add service_tier support for priority processing by @double-di in https://github.com/xai-org/xai-sdk-python/pull/163
• chore: bump version to 1.17.0 by @double-di in https://github.com/xai-org/xai-sdk-python/pull/165

Full Changelog: https://github.com/xai-org/xai-sdk-python/compare/v1.16.0...v1.17.0