[IMP] base: removes storing of res_name from ir.attachment

This commit removes the store property of `res_name` from `ir.attachment`
as it doesn't need to be stored and could contain outdated information
if the record name was changed after the computation.

Task: #1943295

closes odoo/odoo#34930

Signed-off-by: Martin Geubelle (mge) <mge@openerp.com>

addons/mail/views/mail_message_views.xml

@@ -143,7 +143,6 @@
                     <field name="type"/>
                     <field name="create_date"/>
                     <field name="name"/>
-                    <field name="res_name"/>
                     <templates>
                         <t t-name="kanban-box">
                             <div class="oe_kanban_global_area o_kanban_attachment">

odoo/addons/base/models/ir_attachment.py

@@ -36,7 +36,6 @@ class IrAttachment(models.Model):
     _description = 'Attachment'
     _order = 'id desc'
 
-    @api.depends('res_model', 'res_id')
     def _compute_res_name(self):
         for attachment in self:
             if attachment.res_model and attachment.res_id:
@@ -276,7 +275,7 @@ class IrAttachment(models.Model):
 
     name = fields.Char('Name', required=True)
     description = fields.Text('Description')
-    res_name = fields.Char('Resource Name', compute='_compute_res_name', store=True)
+    res_name = fields.Char('Resource Name', compute='_compute_res_name')
     res_model = fields.Char('Resource Model', readonly=True, help="The database object this attachment will be attached to.")
     res_field = fields.Char('Resource Field', readonly=True)
     res_id = fields.Integer('Resource ID', readonly=True, help="The record id this is attached to.")
@@ -372,7 +371,7 @@ class IrAttachment(models.Model):
                 raise AccessError(_("Sorry, you are not allowed to access this document."))
 
     def _read_group_allowed_fields(self):
-        return ['type', 'company_id', 'res_id', 'create_date', 'create_uid', 'res_name', 'name', 'mimetype', 'id', 'url', 'res_field', 'res_model']
+        return ['type', 'company_id', 'res_id', 'create_date', 'create_uid', 'name', 'mimetype', 'id', 'url', 'res_field', 'res_model']
 
     @api.model
     def read_group(self, domain, fields, groupby, offset=0, limit=None, orderby=False, lazy=True):