NocoBase v2.1.8: Locked `@langchain/openai` to patch-level updates for AI packages

🐛 Bug Fixes

• [ai]

  • Locked @langchain/openai to patch-level updates for AI packages. (#9829) by @cgyrock
  • Fixed incompatible LangChain dependency resolution for AI plugins. (#9831) by @cgyrock

• [AI: Knowledge base]

  • Fixed unclear error messages when enabling the AI knowledge base plugin without the AI plugin available. by @cgyrock
  • Fixed incompatible LangChain dependency resolution for the AI knowledge base plugin. by @cgyrock