Update werkzeug requirement from <3 to <4

Updates the requirements on [werkzeug](https://github.com/pallets/werkzeug) to permit the latest version.
- [Release notes](https://github.com/pallets/werkzeug/releases)
- [Changelog](https://github.com/pallets/werkzeug/blob/main/CHANGES.rst)
- [Commits](pallets/werkzeug@0.1...3.0.0)

---
updated-dependencies:
- dependency-name: werkzeug
  dependency-type: direct:production
...

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

requirements.txt

@@ -12,4 +12,4 @@ gunicorn>=20.0.4
 psycopg2-binary>=2.8.6
 southwark>=0.7.1
 sqlalchemy==1.3.22
-werkzeug<3
+werkzeug<4