Allows build_sdist to dereference links

[atuleu]

Currently the sdist step simply copy all symlinks even if they are pointing outside of the build tree.

It would be nice to add an option to force sdist to dereference all links when building the tarball.

A working proof of concept could be found here: main...atuleu:scikit-build-core:main

Would you accept such nre option?, should I open a PR?

[LecrisUT]

See #801. In principal 👍 for this feature. But could you also resolve the linked issue, i.e. if the symlink points outside the sdist root (iiuc it's the folder that contains pyproject.toml) then de-reference it. That should already be there, but it seems that it only applies to files. Ideally for Linux packagers the default of keeping symlinks should be preserved