Prompt linking via propagate_attributes; OpenAI service_tier now captured

What's Changed

• chore(deps): bump the github-actions group with 2 updates by @dependabot[bot] in https://github.com/langfuse/langfuse-python/pull/1746
• fix(langchain): handle Anthropic cache_creation nested dict in usage by @hassiebp in https://github.com/langfuse/langfuse-python/pull/1747
• feat(tracing): support prompt linking via propagate_attributes by @hassiebp in https://github.com/langfuse/langfuse-python/pull/1750
• feat(openai): capture service_tier in model_parameters by @hassiebp in https://github.com/langfuse/langfuse-python/pull/1751

Full Changelog: https://github.com/langfuse/langfuse-python/compare/v4.13.2...v4.14.0