Add support for flakeheaven, fork of flakehell
Name: flakeheaven URL: https://github.com/flakeheaven/flakeheaven
It's a maintained fork of flakehell (https://github.com/flakehell/flakehell) that ALE already supports.
Since flakehell and flakeheaven are almost completely the same, I wonder if the ALE flakehell files could be copied (or refactored) for flakeheaven...
As you mention it would be best to copy flakehell implementation and change all instances of flakehell to flakeheaven. Also if flakehell is not maintained also create an issue to deprecate it.
Before doing all the duplication work it would be good idea to set g:ale_python_flakehell_executable to the flakeheaven executable and check if it works without any further modifications.