Downloading the necessary files all at once instead of doing dependency
handling with luarocks speeds up installation immensely. We speed up the
process even more by using luv as a replacement for the C modules in the
busted dependencies, which allows us to skip costly compilation times.
Co-authored-by: bfredl <bjorn.linse@gmail.com>
Uncrustify is sensitive to version changes, which causes friction for
contributors that doesn't have that exact version. It's also simpler to
download and install the correct version than to have bespoke version
checking.
