Testing: Resolve SADeprecationWarning rucio#5522

Sqlalchemy throws the warning:
```
sqlalchemy.exc.SADeprecationWarning: Invoking or_() without arguments is
deprecated, and will be disallowed in a future release.  For an empty or_()
construct, use or_(False, *args).
```

This comes due to an invalid check of the `rse_clause` variable. If it is an
empty list, the expression `rse_clause is not None` will yield `True`, while it
should be `False`.

lib/rucio/core/replica.py

@@ -819,7 +819,7 @@ def _list_replicas_for_constituents(constituent_clause, state_clause, files_wo_r
     if state_clause is not None:
         constituent_query = constituent_query.filter(and_(state_clause))
 
-    if rse_clause is not None:
+    if rse_clause:
         constituent_query = constituent_query.filter(or_(*rse_clause))
 
     if updated_after: