This update replaces an outdated background style reference that no longer exists. It helps keep Helpdesk and Studio screens displaying consistently after earlier styling changes.

`bg-muted` as been replaced by `bg-200` in odoo/odoo#97051, but there
are still non-converted ones.

The product form now displays planning-related fields in the correct alignment when a product is set as a service. This removes a visual inconsistency in Sales and makes the form easier for users to read and configure.

Step to reproduce:

1. Open Sales
2. Go to product form view
3. Set 'service' as product type
      The planning_role_id field is not correctly aligned with the
      planning_enabled one: https://nimb.ws/6F24re => bug