Fix just executable argument positioning when setting custom flags

[johnhamelink]

This commit changes the justl--parse and justl-exec-eshell functions so that arguments are ordered correctly when calling just: arguments which are destined for just (as in the executable) should be defined before the recipe, since the recipe can have its own arguments.

[johnhamelink]

Umm, when I run ERT locally it passes - is there something wrong with CI?

[psibi]

Umm, when I run ERT locally it passes - is there something wrong with CI?

Don't think so, since it passes in master branch: https://github.com/psibi/justl.el/actions/runs/5921611832/job/16054384296

[johnhamelink]

Ok, maybe my Emacs' state was incorrect, I Will have a look tomorrow evening if I get a chance!

[johnhamelink]

@psibi fixed! I fixed it by accident while thinking about #43

[psibi]

Thank you!