Update uvicorn requirement in /samples/durable-task-sdks/python

Updates the requirements on [uvicorn](https://github.com/Kludex/uvicorn) to permit the latest version.
- [Release notes](https://github.com/Kludex/uvicorn/releases)
- [Changelog](https://github.com/Kludex/uvicorn/blob/main/docs/release-notes.md)
- [Commits](Kludex/uvicorn@0.27.0...0.46.0)

---
updated-dependencies:
- dependency-name: uvicorn
  dependency-version: 0.46.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

samples/durable-task-sdks/python/agent-directed-workflows/requirements.txt

@@ -1,7 +1,7 @@
 durabletask>=1.4.0
 durabletask-azuremanaged>=1.4.0
 fastapi>=0.110.0
-uvicorn>=0.27.0
+uvicorn>=0.46.0
 redis>=5.0.0
 openai>=2.33.0
 azure-identity>=1.25.3

samples/durable-task-sdks/python/arXiv_research_agent/requirements.txt

@@ -11,7 +11,7 @@ azure-identity>=1.25.3
 
 # FastAPI for REST API
 fastapi>=0.109.0
-uvicorn>=0.27.0
+uvicorn>=0.46.0
 
 # HTTP client
 httpx>=0.26.0