build(deps): bump flask

Bumps [flask](https://github.com/pallets/flask) from 2.1.3 to 2.3.2.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@2.1.3...2.3.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/docs/12_task_queues_emails/01_send_emails_python_mailgun/start/requirements.txt

@@ -1,4 +1,4 @@
-flask==2.1.3
+flask==2.3.2
 flask-smorest
 python-dotenv
 sqlalchemy