Bump flask from 2.2.5 to 3.1.3 in /application/single_app

Bumps [flask](https://github.com/pallets/flask) from 2.2.5 to 3.1.3.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@2.2.5...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>

Author: dependabot[bot]

application/single_app/requirements.txt

@@ -1,7 +1,7 @@
 # requirements.txt
 pandas==2.2.3
 azure-monitor-query==1.4.1
-Flask==2.2.5
+Flask==3.1.3
 Flask-WTF==1.2.1
 gunicorn>=23.0.0
 Werkzeug==3.1.5