Bump celery from 5.1.2 to 5.2.2 in /api

Bumps [celery](https://github.com/celery/celery) from 5.1.2 to 5.2.2.
- [Release notes](https://github.com/celery/celery/releases)
- [Changelog](https://github.com/celery/celery/blob/master/Changelog.rst)
- [Commits](celery/celery@v5.1.2...v5.2.2)

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

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

api/requirements.txt

@@ -22,7 +22,7 @@ gunicorn==20.0.4
 drf-spectacular==0.21.1
 # ..................................................................
 # For background work (async work). Redis is the message broker
-celery==5.1.2
+celery==5.2.2
 redis==4.0.0
 # ..................................................................
 # For hard type checking