Bump flask from 3.1.0 to 3.1.1

Bumps [flask](https://github.com/pallets/flask) from 3.1.0 to 3.1.1.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](https://github.com/pallets/flask/compare/3.1.0...3.1.1)

---
updated-dependencies:
- dependency-name: flask
  dependency-version: 3.1.1
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,7 +1,7 @@
 certifi==2025.4.26
 babel==2.17.0
 flask-babel==4.0.0
-flask==3.1.0
+flask==3.1.1
 jinja2==3.1.6
 lxml==5.4.0
 pygments==2.19.1