* Remove remaining support for `secure_backup_setup_methods` option Support for this .well-known setting had been removed everywhere except in a rather obscure corner of the code. There are many other problems with this area (https://github.com/element-hq/element-web/issues/29171) but removing support for the outdated option is an easy step. * Remove remaining `secure_backup_required` setting support Again, this setting was only honoured in the obscure "New Recovery Method" flow.