Explicitly call unique() when joined eader loading

This is one of the differences betwween the legacy API (Query) and the
2.0 API (Select). Ref: https://docs.sqlalchemy.org/en/20/changelog/migration_20.html#orm-rows-not-uniquified-by-default

lib/galaxy/managers/workflows.py

@@ -255,7 +255,7 @@ def name_filter(term):
             stmt = stmt.limit(payload.limit)
         if payload.offset is not None:
             stmt = stmt.offset(payload.offset)
-        return trans.sa_session.scalars(stmt), total_matches
+        return trans.sa_session.scalars(stmt).unique(), total_matches
 
     def get_stored_workflow(self, trans, workflow_id, by_stored_id=True) -> StoredWorkflow:
         """Use a supplied ID (UUID or encoded stored workflow ID) to find