[FIX] mail: avoid generation link preview on internal link

If website is installed, the login page of Odoo has opengraph meta that will be
used to create link preview on mention and channel link.
This PR add a xpath condition to always ignore mention and channel link in the
message body.

Part of task-3000274

closes odoo/odoo#101678

X-original-commit: eb032a5c36af6402b79ae768ce29b3d84eacf3b7
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>
Signed-off-by: Debondt Didier (did) <did@odoo.com>

addons/mail/models/mail_link_preview.py

@@ -29,7 +29,7 @@ class LinkPreview(models.Model):
         if not message.body:
             return
         tree = html.fromstring(message.body)
-        urls = tree.xpath('//a/@href')
+        urls = tree.xpath('//a[not(@data-oe-model)]/@href')
         link_previews = self.env['mail.link.preview']
         requests_session = requests.Session()
         # Some websites are blocking non browser user agent.