Bump werkzeug from 3.0.3 to 3.0.4 in /backend/src

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 3.0.3 to 3.0.4.
- [Release notes](https://github.com/pallets/werkzeug/releases)
- [Changelog](https://github.com/pallets/werkzeug/blob/main/CHANGES.rst)
- [Commits](pallets/werkzeug@3.0.3...3.0.4)

---
updated-dependencies:
- dependency-name: werkzeug
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

backend/src/requirements.txt

@@ -4,5 +4,5 @@ Flask==3.0.3
 itsdangerous==2.2.0
 Jinja2==3.1.4
 MarkupSafe==2.1.5
-Werkzeug==3.0.3
+Werkzeug==3.0.4
 gunicorn==23.0.0