Fix make with luarocks not working

[Frityet]

Before this fix, teal would get confused when you would do make LUA=./lua where ./lua would be the local lua scripts that luarocks make, because the actual teal transpiler uses the modules from ./teal but tlcli would use it from ./lua_modules/bin/share/lua/5.X which causes errors. Furthermore, the tests only set package.path, not package.cpath which made them fail if the modules (lfs) was only in lua_modules

[github-actions]

Teal Playground URL: https://1050--teal-playground-preview.netlify.app