Update flask requirement from ~=2.1.2 to ~=2.2.2 in /api

Updates the requirements on [flask](https://github.com/pallets/flask) to permit the latest version.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](https://github.com/pallets/flask/compare/2.1.2...2.2.2)

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

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

api/requirements.txt

@@ -1,4 +1,4 @@
-Flask~=2.1.2
+Flask~=2.2.2
 python-dotenv==0.20.0
 uwsgi==2.0.20
 Flask_SQLAlchemy==2.5.1