lantiq-xrx200 is currently marked as source-only in OpenWrt 23.05, as
the switch driver does not work correctly on Linux 5.15. Mark as broken
in Gluon as well until the issue is fixed.

Upstream PR: https://github.com/openwrt/openwrt/pull/13200

as well as the target itself

Co-authored-by: Jan-Niklas Burfeind <github@aiyionpri.me>

Re-add mikrotik target

Note that previous images were generic ones and as such no migration
path is provided other than manually flashing the image via config-mode.

The scripts directory contains most of our build system, so changing it
should trigger a build of all targets.