Bump flask from 2.2.3 to 2.3.3

Bumps [flask](https://github.com/pallets/flask) from 2.2.3 to 2.3.3.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@2.2.3...2.3.3)

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

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

requirements.txt

@@ -2,7 +2,7 @@ Authlib==0.8
 flask-session==0.4.0
 loginpass==0.1.1
 coverage==7.3.1
-Flask==2.2.3
+Flask==2.3.3
 Flask-Markdown==0.3
 Flask-WTF==1.0.1
 ItsDangerous==2.1.2