Enhance CI

[SuperFola]

CI should either

• build Ark from the latest buildable commit on dev,
• or download an artifact generated by a CI on the core repository,

so that we have the latest functionnalities available to us on this CI (the CI on the core repository is running the std lib tests with the latest commit but here we use the latest release).

If we go with option 2, we'll have to update a linux CI on the core repository to generate CI artifacts somehow (I know it's possible, but I don't know how it works, nor how we can do that ; I've only read a few things about that on the Internet)

[SuperFola]

I added build artifacts in ArkScript-lang/Ark#263

Using https://github.com/dawidd6/action-download-artifact, we should be able to retrieve the latest build artifact from the dev branch of Ark