[FIX] stock_manual_transfer: Correct model name for Preferred Route i…

…n v15.0

Changed the model name from 'stock.route' to 'stock.location.route' in
the field definition of 'route_id' to ensure compatibility with Odoo
v15.0. The incorrect model name was causing the following validation
error during view rendering:
```
Error while validating view near:
Unknown field "_unknown.supplied_wh_id" in domain of field 'route_id'
```

Was fixed by update route_id field definition with model stock.location.route

stock_manual_transfer/models/stock_manual_transfer.py

@@ -28,7 +28,7 @@ class StockManualTransfer(models.Model):
         states={"draft": [("readonly", False)]},
     )
     route_id = fields.Many2one(
-        "stock.route",
+        "stock.location.route",
         string="Preferred Route",
         domain="""[
             ('manual_transfer_selectable', '=', True),