[FIX] fields: do not attempt to set foreign keys on views

Users sometimes define custom models on SQL views
e.g. @nseinlet
In such a case, Odoo should not attempt to create foreign keys
as it just cannot work on views.

This could prevent the migration of a database
with such a custom model using a view
when it attempted to fix the missing foreign keys
when updating the modules.

closes odoo/odoo#38951

Signed-off-by: Christophe Simonis <chs@odoo.com>

odoo/fields.py

@@ -1962,6 +1962,9 @@ class Many2one(_Relational):
 
     def update_db_foreign_key(self, model, column):
         comodel = model.env[self.comodel_name]
+        # foreign keys do not work on views, and users can define custom models on sql views.
+        if not model._is_an_ordinary_table() or not comodel._is_an_ordinary_table():
+            return
         # ir_actions is inherited, so foreign key doesn't work on it
         if not comodel._auto or comodel._table == 'ir_actions':
             return