Fix OPDS circulation-only updates being skipped after hash-based detection

The `opds_import_task` was not passing `apply_circulation` to
`importer.import_feed`, making the fallback path for "bibliographic
unchanged, circulation changed" completely dead code. Pass
`apply.circulation_apply.delay` to restore that path.
Add a `needs_apply` guard to the `elif` branch in
`import_feed_from_response` so `apply_circulation` is only queued when
the circulation data has actually changed, preventing redundant tasks on
every re-import of unchanged content.
Fix `CirculationData.needs_apply` to always return `True` when
`self.licenses` is not None (ODL-style pools). License expiry is
time-dependent and cannot be detected by content hashing alone; this
mirrors the existing exception already present in the `apply()` early-
return guard.

Author: dbernstein

src/palace/manager/data_layer/circulation.py

@@ -395,9 +395,16 @@ def needs_apply(self, session: Session, collection: Collection) -> bool:
         for this object's primary identifier in *collection* and delegates to
         :meth:`~palace.manager.data_layer.base.mutable.BaseMutableData.should_apply_to`.
 
+        ODL-style pools that carry individual :attr:`licenses` are always considered to
+        need application because license availability can change over time as licenses expire
+        independently of any feed content change, and that expiry cannot be detected by
+        content hashing alone.
+
         :param session: Active database session used to look up the pool.
         :param collection: The collection the pool belongs to.
         :return: ``True`` if the data needs to be applied, ``False`` if it can be skipped.
         """
+        if self.licenses is not None:
+            return True
         pool, _ = self.license_pool(session, collection, autocreate=False)
         return self.should_apply_to(pool)