[FIX] website: allow editor users to edit theme views

Currently, "Editor and Designer" can't edit the views which originate
from a theme (which are copies from the theme `theme.ir.ui.view`
records).

This error is caused by [1], which is preventing the `arch_updated`
field to be set to `True`, as this field is supposed to be set to `True`
only on manual user change, not during module update.

Indeed, restricted users don't have access to the themes records, making
the overide raising an error.

But there were actually no reason for this code to be executed outside
module operation.

Steps to reproduce:
- Create any view in a theme module.
  For example: create a custom footer view.
- As a "Editor and Designer" user, edit this view through the website
  builder.
- An access right error is raised.

[1]: https://github.com/odoo/odoo/commit/1eb7c577ecb31c2f0876b6dd76769e2b47802cb0



closes odoo/odoo#88990

Signed-off-by: Romain Derie (rde) <rde@odoo.com>