build(deps): update dependency celery to v5.2.6

requirements.txt

@@ -26,7 +26,7 @@ brotli==1.0.9
     # via -r requirements.in
 calmjs.parse==1.3.0
     # via -r requirements.in
-celery[msgpack,pytest,redis]==5.1.2
+celery[msgpack,pytest,redis]==5.2.6
     # via
     #   -r requirements.in
     #   pytest-celery