[FIX+IMP] rma_sale: Proper dependency + propagate salesman

- Proper dependency is `sale_stock`, not `sale`, as we are using some fields added
  by this module.
- Propagate salesman from sales order when available.

TT25525

rma_sale/__manifest__.py

@@ -12,7 +12,7 @@
     "license": "AGPL-3",
     "depends": [
         "rma",
-        "sale",
+        "sale_stock",
     ],
     "data": [
         "views/assets.xml",

rma_sale/models/rma.py

@@ -81,3 +81,10 @@ class Rma(models.Model):
     @api.onchange('order_id')
     def _onchange_order_id(self):
         self.product_id = self.picking_id = False
+
+    def _prepare_refund(self, invoice_form, origin):
+        """Inject salesman from sales order (if any)"""
+        res = super()._prepare_refund(invoice_form, origin)
+        if self.order_id:
+            invoice_form.user_id = self.order_id.user_id
+        return res

rma_sale/tests/test_rma_sale.py

@@ -70,3 +70,16 @@ class TestRmaSale(SavepointCase):
             rma.reception_move_id.picking_id + self.order_out_picking,
             order.picking_ids,
         )
+        # Refund the RMA
+        user = self.env["res.users"].create(
+            {
+                "login": "test_refund_with_so",
+                "name": "Test",
+            }
+        )
+        order.user_id = user.id
+        rma.action_confirm()
+        rma.reception_move_id.quantity_done = rma.product_uom_qty
+        rma.reception_move_id.picking_id.action_done()
+        rma.action_refund()
+        self.assertEqual(rma.refund_id.user_id, user)