[test] Replace symlinks in legacy_cubes by real copies This solves a "python setup.py build" issue on my machine. Copying these files should not be a big deal because they have been dropped in the "default" branch and we would not touch them in 3.26 branch.

[bdist_wheel]
universal = 1

[check-manifest]
ignore =
  debian
  debian/*
  cubicweb.spec
  __pkginfo__.py