Update IN_STOCK_FILTER to reject stock items which have is_building set to True

InvenTree/stock/models.py

@@ -143,6 +143,7 @@ class StockItem(MPTTModel):
         build_order=None,
         belongs_to=None,
         customer=None,
+        is_building=False,
         status__in=StockStatus.AVAILABLE_CODES
     )