Migrate current callers to level-indexed refinement API

tests/validation/time_window_dfg.py

@@ -73,7 +73,7 @@ def run_variant(backend, variant, n_intervals, deadline):
             else:
                 for _ in range(INTERVAL):
                     backend.step(1)
-            totals.append(components(backend.read_exchange_window(0)))
+            totals.append(components(backend.read_exchange_window(0, level=1)))
         t.check_deadline(deadline)
     return np.array(totals), (np.array(scales) if scales else None)