[REM] mail: remove dead controllers

Some controllers are not called anymore. Let us remove them to remove
unnecessary entry points.

Task-2631873
PR odoo/odoo#75571

addons/mail/controllers/discuss.py

@@ -94,24 +94,10 @@ class DiscussController(http.Controller):
         response.status = str(status)
         return response
 
-    @http.route('/mail/needaction', type='json', auth='user')
-    def needaction(self):
-        return request.env.user.partner_id._get_needaction_count()
-
     @http.route('/mail/init_messaging', type='json', auth='user')
     def mail_init_messaging(self):
         return request.env.user._init_messaging()
 
-    @http.route('/mail/get_partner_info', type='json', auth='user')
-    def message_partner_info_from_emails(self, model, res_ids, emails, link_mail=False):
-        records = request.env[model].browse(res_ids)
-        try:
-            records.check_access_rule('read')
-            records.check_access_rights('read')
-        except:
-            return []
-        return records._message_partner_info_from_emails(emails, link_mail=link_mail)
-
     @http.route('/mail/get_suggested_recipients', type='json', auth='user')
     def message_get_suggested_recipients(self, model, res_ids):
         records = request.env[model].browse(res_ids)

addons/mail/controllers/mail.py

@@ -152,13 +152,3 @@ class MailController(http.Controller):
         if res_id and isinstance(res_id, str):
             res_id = int(res_id)
         return self._redirect_to_record(model, res_id, access_token, **kwargs)
-
-    @http.route('/mail/assign', type='http', auth='user', methods=['GET'])
-    def mail_action_assign(self, model, res_id, token=None):
-        comparison, record, redirect = self._check_token_and_record_or_redirect(model, int(res_id), token)
-        if comparison and record:
-            try:
-                record.write({'user_id': request.uid})
-            except Exception:
-                return self._redirect_to_messaging()
-        return redirect