fix(sp41): drop unused Decimal import from pipeline_b

backend/src/cyclone/rebill/pipeline_b.py

@@ -11,7 +11,6 @@ override flag is the same for the whole batch (a per-batch override).
 from collections import defaultdict
 from dataclasses import dataclass
 from datetime import date
-from decimal import Decimal
 from pathlib import Path
 
 from cyclone.rebill.reconcile import VisitRow
@@ -113,4 +112,4 @@ def write_pipeline_b_files(
         path = out_dir / fname
         path.write_text(body, encoding="ascii")
         paths.append(path)
-    return paths
+    return paths