chore(deps): update uvicorn requirement in /backend

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@0.32.0...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]

backend/requirements.txt

@@ -1,6 +1,6 @@
 # Backend Dependencies
 fastapi>=0.115.0
-uvicorn[standard]>=0.32.0
+uvicorn[standard]>=0.46.0
 httpx>=0.27.0
 python-dotenv>=1.0.0
 pydantic>=2.0.0