Bump flask from 2.0.3 to 2.1.1

Bumps [flask](https://github.com/pallets/flask) from 2.0.3 to 2.1.1.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@2.0.3...2.1.1)

---
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

@@ -3,7 +3,7 @@ bs4==0.0.1
 certifi==2021.10.8
 charset-normalizer==2.0.12
 click==8.1.0
-Flask==2.0.3
+Flask==2.1.1
 idna==3.3
 itsdangerous==2.1.1
 Jinja2==3.0.3