export-ignore in .gitattributes

[jbboehr]

I set up export-ignore in my .gitattributes because I have ~1MB of generated lockfiles that are totally only used by CI and wanted to save some space for the tarballs generated by GitHub, but it looks like the hercules-ci-agent might be fetching the sources from the tarballs (or something else that respects export-ignore).

I think it would make sense to NOT respect export-ignore, because, from my experience, testing files are marked this way and that's exactly what CI should do.

IIRC (and my memory may be totally wrong) builtins.fetchgit uses git archive which follows export-ignore but pkgs.fetchGit does not.

Not a huge deal, but would be nice to have.