Bump celery in /{{cookiecutter.project_slug}}/backend

Bumps [celery](https://github.com/celery/celery) from 5.0.0 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@v5.0.0...v5.2.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

{{cookiecutter.project_slug}}/backend/requirements.txt

@@ -1,7 +1,7 @@
 alembic==1.4.3
 Authlib==0.14.3
 fastapi==0.65.2
-celery==5.0.0
+celery==5.2.2
 redis==3.5.3
 httpx==0.15.5
 ipython==7.18.1