We now require the following to ge given in the cli args:
- zig_exe
- build_root
- cache_root
- global_cache_root
This fixes the path for packages that use one or more from the above to place
their files.
I'm not 100% sure if the `GeneratedFile`'s path will have been resolved when this code runs or if this will hit the panic inside `getPath()` as I havent had a chance to actually mess about with the new functionality.
in the destination folder. Instead, it will use a specific cache folder
and run from the default cwd it was run from.
Added build_runner_cache_path to the configuration file.
