Async streaming for bedrock chat

[villekr]

Currently langchain with Bedrock doesn't support async streaming for chat requests. With sync streaming we can't show reponses while they are streamed from bedrock. Currently sync responses are in use and wait indicator is shown.

Depends on: langchain-ai/langchain#17113

[villekr]

Fixed in https://github.com/villekr/paita/releases/tag/0.1.13 by depending on latest langchain-aws, which correctly supports bedrock async requests.