build(deps): bump uvicorn from 0.38.0 to 0.40.0 in /backend

Bumps [uvicorn](https://github.com/Kludex/uvicorn) from 0.38.0 to 0.40.0.
- [Release notes](https://github.com/Kludex/uvicorn/releases)
- [Changelog](https://github.com/Kludex/uvicorn/blob/main/docs/release-notes.md)
- [Commits](Kludex/uvicorn@0.38.0...0.40.0)

---
updated-dependencies:
- dependency-name: uvicorn
  dependency-version: 0.40.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]