chore: update fastapi dev dependency to fix vulnerability report (#1182)

https://github.com/langchain-ai/langsmith-sdk/security/dependabot/31 --
getting flagged in vanta

only a dev dep, but easy enough to do anyways

Author: nfcampos

python/poetry.lock

@@ -54,7 +54,7 @@ pytest-cov = "^4.1.0"
 dataclasses-json = "^0.6.4"
 types-tqdm = "^4.66.0.20240106"
 vcrpy = "^6.0.1"
-fastapi = "^0.110.1"
+fastapi = "^0.115.4"
 uvicorn = "^0.29.0"
 pytest-rerunfailures = "^14.0"
 pytest-socket = "^0.7.0"