Source: lunarmodules/busted@b072ae9

After seeing there's an action to download LuaRocks, I'm embarrassed I didn't google this first. I guess I just assumed no one had bothered to create one as the Lua ecosystem is pretty much dead usually.

Should probably review what they're doing. In case it has significant overhead, we likely would prefer the manual download even if it's more verbose as the CI is expected to run very frequently currently (on each commit that's pushed).