[FIX] website: restore proper uninstallation of the website app

Before this commit, we had an error following those steps:

1. Install website app.
2. Customize the first website default theme settings (like the
   font-size of the header logo).
3. Uninstall the website app.
4. Reinstall the website app.
5. Try step (2) again => It does not work.

This is due to custom SCSS attachments which were not properly removed
after we uninstalled the app. The problem was actually already solved
at some point with [1] but was later broken by [2] which prevented to
properly call the `unlink` method for the only remaining website.

[1]: odoo@2f361be
[2]: odoo@93a2e85

Fixes odoo#44240
opw-2947919

closes odoo#97874

X-original-commit: 4658afd
Signed-off-by: Romain Derie (rde) <[email protected]>
Signed-off-by: Quentin Smetz (qsm) <[email protected]>

Author: qsm-odoo

addons/website/models/website.py

@@ -13,6 +13,7 @@
 from werkzeug.exceptions import NotFound
 
 from odoo import api, fields, models, tools, http
+from odoo.addons.base.models.ir_model import MODULE_UNINSTALL_FLAG
 from odoo.addons.http_routing.models.ir_http import slugify, _guess_mimetype, url_for
 from odoo.addons.website.models.ir_http import sitemap_qs2dom
 from odoo.addons.portal.controllers.portal import pager
@@ -238,9 +239,11 @@ def _handle_favicon(self, vals):
             vals['favicon'] = tools.image_process(vals['favicon'], size=(256, 256), crop='center', output_format='ICO')
 
     def unlink(self):
-        website = self.search([('id', 'not in', self.ids)], limit=1)
-        if not website:
-            raise UserError(_('You must keep at least one website.'))
+        if not self.env.context.get(MODULE_UNINSTALL_FLAG, False):
+            website = self.search([('id', 'not in', self.ids)], limit=1)
+            if not website:
+                raise UserError(_('You must keep at least one website.'))
+
         # Do not delete invoices, delete what's strictly necessary
         attachments_to_unlink = self.env['ir.attachment'].search([
             ('website_id', 'in', self.ids),