`quarto run` should support also Julia script for all `engine: julia` use case where Julia is the primary language

[cderv]

We do allow R and Python for project script, with quarto run or pre / post render script

• https://quarto.org/docs/projects/scripts.html#periodic-scripts

We should probably add support for Julia.

Probably just a matter of new run handler for Julia
https://github.com/quarto-dev/quarto-cli/blob/75d1c6085440e54a6035de1f93612d6435c397ff/src/core/run/register.ts#L7-L11

[cscheid]

I think it might be a good idea to associate the run handlers with engines, so when we make engines extensible, adding a new engine will also add the run handler. Presumably, people who want one will also want the other.