Build arkindex source code with nuitka, but do not expose as docker image
Refs https://redmine.teklia.com/issues/5678
This brings a simpler CI task to build arkindex with nuitka, but without building a working docker image around that binary.
We just want to know that Arkindex remains "compilable" with Nuitka for enterprise version.
After 1.5.3 is done, we'll remove the binary build from here