[FIX] mail: close RTC session when leaving a channel

When a user leave a channel with an RTC session open, we need to notify others
user and remove the leaving user from the room.

task-2646095

closes odoo/odoo#76719

X-original-commit: 6b498a0969b63e190637f112c6a7d5f8177c772c
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/models/mail_channel_partner.py

@@ -65,6 +65,10 @@ class ChannelPartner(models.Model):
                     raise AccessError(_('You can not write on %(field_name)s.', field_name=field_name))
         return super(ChannelPartner, self).write(vals)
 
+    def unlink(self):
+        self.sudo().rtc_session_ids.unlink()
+        return super().unlink()
+
     @api.model
     def _get_as_sudo_from_request_or_raise(self, request, channel_id):
         channel_partner = self._get_as_sudo_from_request(request=request, channel_id=channel_id)