Bump flask in /code-samples/eventing/helloworld/helloworld-python (#6577)

Bumps [flask](https://github.com/pallets/flask) from 2.3.2 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@2.3.2...3.1.3)

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

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Author: dependabot[bot]

code-samples/eventing/helloworld/helloworld-python/requirements.txt

@@ -1 +1 @@
-Flask==2.3.2
+Flask==3.1.3