uutests: add LICENSE

[michel-slm]

Symlink LICENSE from the project root so it gets picked up when packaging

coreutils/tests/uutests on uutests-add-license
$ cargo package --allow-dirty --list | grep LICENSE

coreutils/tests/uutests on uutests-add-license
$ ln -s ../../LICENSE .

coreutils/tests/uutests on uutests-add-license
$ cargo package --allow-dirty --list | grep LICENSE
LICENSE

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/follow-name (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/expand/bounded-memory is now passing!

[oech3]

I s it able to remove all symlinks instead? cargo should handle them autimatically.

[michel-slm]

@oech3 cargo handles symlinks just fine, I've been sending similar fixes to include license files for multiple projects that have a single git repo with multiple crates all with the same license as part of the Fedora Rust SIG.

Happy to entertain other suggestions, but as you notice, src/uucore/LICENSE is also a symlink - this is a common pattern, it's just that it got missed with newer crates.

[oech3]

Those symlinks break .zip on Windows. Would you consider removing them instrad?
This is really probrematic for the case we want to build *.exe from zip.

See also #9489 (comment)

cargo workspace is able to add the license flag to inherit the parent package licensing infromation, this symlink PR is no longer neccesary