[FIX] website: make generated templates noupdate

Since [1] when the generation of missing configurator templates and new
page templates was introduced, `_load_xmlid` was called for every
generated record so that `_process_end` does not delete them after a
module update.
Unfortunately, this trick does not work when using the "Upgrade" command
on the Website app in the Apps view. (or calling
```py
env['ir.module.module'].search([
    ('name', '=', 'website')
]).button_immediate_upgrade()`
```
from the shell): in that case, the `self.pool` onto which the xmlids
were registered was a different instance from the one accessed by
`_process_end`.

This commit avoids this problem by making the generated templates
`noupdate: True`, thus preventing `_process_end` from deleting them.

Steps to reproduce:
- Install website with -i
- Go to Apps, search Website, upgrade Website
=> In the logs you can see that some templates are deleted at the end of
   the upgrade
- Website configurator: a business website, furniture store, get leads,
  choose a palette, about us + services + pricing + privacy policy,
  choose the center template (loftspace)
=> You see some crash in the logs

[1]: https://github.com/odoo/odoo/commit/a2f8e18b76e52e1a349b77691d0af18edc09a1be

closes odoo/odoo#140986

Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/website/models/ir_module_module.py

@@ -568,11 +568,17 @@ class IrModuleModule(models.Model):
 
             :param views: views for which model data must be created
         """
+        # The generated templates are set as noupdate in order to avoid that
+        # _process_end deletes them.
+        # In case some of them require an XML definition in the future,
+        # an upgrade script will be needed to temporarily make those
+        # records updatable.
         self.env['ir.model.data'].create([{
             'name': view.key.split('.')[1],
             'module': view.key.split('.')[0],
             'model': 'ir.ui.view',
             'res_id': view.id,
+            'noupdate': True,
         } for view in views])
 
     def _generate_primary_snippet_templates(self):
@@ -605,11 +611,6 @@ class IrModuleModule(models.Model):
             missing_create_values = [values for values in create_values if values['key'] not in existing_primary_template_keys]
             missing_records = self.env['ir.ui.view'].with_context(no_cow=True).create(missing_create_values)
             self._create_model_data(missing_records)
-
-            # Prevent deletion by _process_end
-            for values in create_values:
-                self.env['ir.model.data']._load_xmlid(values["key"])
-
             return len(missing_records)
 
         def get_create_vals(name, snippet_key, parent_wrap, new_wrap):
@@ -779,8 +780,5 @@ class IrModuleModule(models.Model):
             missing_records = View.create(missing_create_values)
             self._create_model_data(missing_records)
             _logger.info('Generated %s primary page templates for %r', len(missing_create_values), self.name)
-        # Prevent deletion by _process_end
-        for values in create_values:
-            self.env['ir.model.data']._load_xmlid(values['key'])
         if update_count:
             _logger.info('Updated %s primary page templates for %r', update_count, self.name)