Bump flask from 1.0 to 2.3.2

Bumps [flask](https://github.com/pallets/flask) from 1.0 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@1.0...2.3.2)

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

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

requirements.txt

@@ -1,7 +1,7 @@
 click==6.7
 dice==1.1.1
 docopt==0.6.2
-Flask==1.0
+Flask==2.3.2
 gunicorn==19.10.0
 itsdangerous==0.24
 Jinja2==2.11.3