langchain-openai 1.6.1

Changes since langchain-openai==1.6.0

fix(openai): bump max_completion_tokens in cache breakpoint integration test (#40284) release(openai): 1.6.1 (#40268) chore(model-profiles): refresh model profile data (#40217) fix(openai): support Azure AD auth with OpenAI 3.8 (#40190) feat(openai): support async tools (#40208) feat(openai): support configuration_update (#40201) chore(model-profiles): refresh model profile data (#40171) fix(openai): route gpt-5.6-sol to responses API (#40133) chore(openai): fix tests (#39972) fix(openai): correct reasoning_effort_levels for gpt-5 and gpt-5.1 profiles (#39936) chore(model-profiles): refresh model profile data (#39954)