Support for scripts/headers dirs for wheel build hooks

[henryiii]

Currently, there's a mechanism for package files (force-include), shared data (shared-data), and even metadata (extra-metadata), but no matching entries for the other two wheel folders: /scripts and /headers. At least scripts would be useful, as binary applications sometimes need to be installed there (like ruff from Ruff, for example). IMO, it would be nice to support headers too, since it exists, even though it's pretty lightly used (and buggy in setuptools).

[ofek]

I'm not going to do headers until I hear a use case