Bump flask from 1.1.2 to 2.1.2

Bumps [flask](https://github.com/pallets/flask) from 1.1.2 to 2.1.2.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@1.1.2...2.1.2)

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

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

Author: dependabot[bot]

requirements.txt

@@ -1,5 +1,5 @@
 sqlalchemy==1.4.37
-flask==1.1.2
+flask==2.1.2
 passlib==1.7.4
 pymysql==1.0.2
 python-magic==0.4.26