Changes since langchain==1.4.2 release(langchain): 1.4.3 ( #40888 ) fix(langchain): sanitize cache settings for fallback models ( #40886 ) feat(langchain): support Bedrock Mantle chat models in init_chat_model ( #40837 ) fix(langchain): recognize GPT-6 structured output without profiles ( #40844 ) docs(infra): fix AGENTS.md root setup guidance and package doc accuracy ( #40794 ) fix(langchain): repair invalid tool calls in create_agent ( #40530 ) chore(langchain): remove commented-out cohere ext