libjade: update license: CC0-1.0 OR Apache-2.0

[tfaoliveira]

This PR updates libjade to a dual license (previously CC0, now CC0 and Apache).

Motivation: allow libjade to be integrated by other libraries, for instance, open-quantum-safe/liboqs#1745

Note: I plan to propagate these changes to all branches in libjade.

I will request a review from libjade contributors so they can acknowledge this license update:

• I can assign up to 15 reviewers to this PR; these will be the first 15 from git shortlog -sne --all
• The remaining will be tagged in a comment, and they can react with a +1 if they are OK with the license change

[tfaoliveira]

@ruipedro16
@praveksharma
@loutr
@claucece

[eponier]

My only contribution to libjade is updating a hash, so I do not think you need my approval, but here it is anyway.

[vbgl]

Can someone please elaborate how the current CC0 license forbids to distribute libjade under the Apache license?

[vincentvbh]

open-quantum-safe/liboqs#1388

[dsprenkels]

LGTM.

I do not own any patents over the code that I wrote, nor do I know of any relevant patents for the code that I wrote.