Bump flask from 3.0.3 to 3.1.0 in /src (#4040)

Bumps [flask](https://github.com/pallets/flask) from 3.0.3 to 3.1.0.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@3.0.3...3.1.0)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/requirements.txt

@@ -1,4 +1,4 @@
-flask==3.0.3
+flask==3.1.0
 flask-talisman==1.1.0
 gunicorn==22.0.0
 pytest==8.2.2