Citation metadata surfaced; stop sequences supported

Changes since langchain-mistralai==1.1.5

release(mistralai): 1.1.6 (#38684) feat(mistralai): surface citation metadata from chat responses (#37008) chore(model-profiles): refresh model profile data (#38663) chore: bump vcrpy from 8.1.1 to 8.2.1 in /libs/partners/mistralai (#38302) chore: bump langsmith from 0.8.5 to 0.8.18 in /libs/partners/mistralai (#38304) chore(model-profiles): refresh model profile data (#38210) docs: refresh README installation and resources (#38119) release(core): 1.4.7 (#38111) fix(core,partners): rename package version trace metadata (#38110) style(core,langchain,langchain-classic,partners): replace double backticks in docstrings (#38095) release(core): 1.4.6 (#38061) feat(core,partners): add package version tracking to tracing metadata (#35295) chore(infra): bump mypy to 2.1 and unify type-check config across the monorepo (#36470) feat(mistralai): support stop sequences (#38047)