LangChain 1.7.3

Changes since langchain-openai==1.7.2

test(openai): use current lightweight model in integration tests (#41509)
release(openai): 1.7.3 (#41506)
chore(model-profiles): refresh openai model profile data (#41505)
build(infra): patch test-only Pillow without dropping Python 3.10 (#41484)
revert: patch vulnerable integration dependencies (#41481)
build(deps): patch vulnerable integration dependencies (#41473)
chore(infra): relax third-party dependency upper bounds (#41407)
chore(deps): bump aiohttp from 3.14.4 to 3.14.5 in /libs/partners/openai (#41379)
chore(deps): bump certifi from 2025.10.5 to 2026.10.19 in /libs/partners/openai (#41380)
chore(deps): bump aiohttp from 3.14.3 to 3.14.4 in /libs/partners/openai (#41362)
chore(model-profiles): refresh model profile data (#41325)
chore(deps): bump pytest from 9.0.3 to 9.1.1 in /libs/partners/openai (#41328)
chore(deps): bump pygments from 2.20.0 to 2.21.0 in /libs/partners/openai (#41333)
chore(deps): bump requests from 2.33.0 to 2.34.2 in /libs/partners/openai (#41331)
chore(deps): bump orjson from 3.11.6 to 3.13.0 in /libs/partners/openai (#41329)
fix: fix dependencies in some partner packages (#41266)