community/erlang: upgrade to 26.1.2

ejabberd, lfe, and rebar3 seem to work alright without a rebuild, so they have been left out of this MR.

cloudi requires two upstream patches to build without erroring out.

Finally, rabbitmq-server has been upgraded, because according to the version requirements, the current 3.12.0 does not support Erlang 26.1.