Bump flask from 3.0.0 to 3.1.3

Bumps [flask](https://github.com/pallets/flask) from 3.0.0 to 3.1.3.
- [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/3.0.0...3.1.3)

---
updated-dependencies:
- dependency-name: flask
  dependency-version: 3.1.3
  dependency-type: direct:production
...

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

requirements.txt

@@ -2,7 +2,7 @@ alembic==1.7.5
 autopep8==1.6.0
 bcrypt==4.0.1
 email-validator==1.1.3
-Flask==3.0.0
+Flask==3.1.3
 Flask-APScheduler==1.12.3
 Flask-Assets==2.1.0
 Flask-Migrate==3.1.0