[FIX] website_project_issue: No buttons for portal, customers

Customers without an user account can do nothing with the button
in the notification, so it's better they don't have it.

partial backport of #4732a1

This commit closes #22487

addons/website_project_issue/models/project_issue.py

@@ -36,6 +36,9 @@ class Issue(models.Model):
         groups = super(Issue, self)._notification_recipients(message, groups)
 
         for group_name, group_method, group_data in groups:
+            if group_name in ["customer", "portal"]:
+                continue
+
             group_data['has_button_access'] = True
 
         return groups