[FIX] stock: create line in readonly mode

This commit creates the stock move line in readonly to be able to focus
out the move_line_ids one2many widget without having to confirm the
values of all the move line with a <Enter> key

Part-of: odoo/odoo#136067

addons/stock/static/src/widgets/generate_serial.js

@@ -49,7 +49,7 @@ export class GenerateDialog extends Component {
         for (const values of move_line_vals) {
             newlines.push(
                 lines._createRecordDatapoint(values, {
-                    mode: 'edit',
+                    mode: 'readonly',
                     virtualId: getId("virtual"),
                     manuallyAdded: false,
                 })