Bump werkzeug from 3.0.1 to 3.0.3 in /src/Backend

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 3.0.1 to 3.0.3.
- [Release notes](https://github.com/pallets/werkzeug/releases)
- [Changelog](https://github.com/pallets/werkzeug/blob/main/CHANGES.rst)
- [Commits](pallets/werkzeug@3.0.1...3.0.3)

---
updated-dependencies:
- dependency-name: werkzeug
  dependency-type: indirect
...

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