chore(deps): update celery requirement from ~=5.2.7 to ~=5.3.0 in /api

Updates the requirements on [celery](https://github.com/celery/celery) to permit the latest version.
- [Release notes](https://github.com/celery/celery/releases)
- [Changelog](https://github.com/celery/celery/blob/main/Changelog.rst)
- [Commits](celery/celery@v5.2.7...v5.3.0)

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

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

api/requirements.txt

@@ -1,5 +1,5 @@
 captcha~=0.4.0
-celery~=5.2.7
+celery~=5.3.0
 coverage~=7.2.7
 cryptography~=41.0.1
 Django~=4.1.0  # upgrade once django-pgtrigger is compatible