Bump flask-session from 0.5.0 to 0.6.0 in /app

Bumps [flask-session](https://github.com/pallets-eco/flask-session) from 0.5.0 to 0.6.0.
- [Release notes](https://github.com/pallets-eco/flask-session/releases)
- [Changelog](https://github.com/pallets-eco/flask-session/blob/main/CHANGES.rst)
- [Commits](https://github.com/pallets-eco/flask-session/commits)

---
updated-dependencies:
- dependency-name: flask-session
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

app/requirements.txt

@@ -1,5 +1,5 @@
 Flask==3.0.2
 flask-paginate==2023.10.24
-Flask-Session==0.5.0
+Flask-Session==0.6.0
 gunicorn==21.2.0
 requests==2.31.0