Bump werkzeug from 3.1.5 to 3.1.6 in /flask

Bumps [werkzeug](https://github.com/pallets/werkzeug) from 3.1.5 to 3.1.6.
- [Release notes](https://github.com/pallets/werkzeug/releases)
- [Changelog](https://github.com/pallets/werkzeug/blob/main/CHANGES.rst)
- [Commits](pallets/werkzeug@3.1.5...3.1.6)

---
updated-dependencies:
- dependency-name: werkzeug
  dependency-version: 3.1.6
  dependency-type: direct:production
...

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

Author: dependabot[bot]

flask/requirements.txt

@@ -8,5 +8,5 @@ Jinja2==3.1.6
 MarkupSafe==2.0.1
 python-dotenv==0.17.1
 visitor==0.1.3
-Werkzeug==3.1.5
+Werkzeug==3.1.6
 WTForms==2.2.1