[FIX] rma: avoid refunding in picking return wizard

If we place an RMA from the stock picking return wizard, we want to
avoid setting the new moves to refund as that will affect the related
sale lines delivered quantities count.

TT42021

rma/wizard/stock_picking_return.py

@@ -29,6 +29,9 @@ class ReturnPicking(models.TransientModel):
                 [("company_id", "=", self.picking_id.company_id.id)]
             ).mapped("rma_loc_id")
             rma_loc_domain = [("id", "child_of", rma_loc.ids)]
+            # We want to avoid setting the return move `to_refund` as it will change
+            # the delivered quantities in the sale and set them to invoice.
+            self.product_return_moves.to_refund = False
         else:
             # If self.create_rma is not True, the value of the location and
             # the location domain will be the same as assigned by default.