spdx: Make CC-BY-3.0 and CC-BY-SA-3.0 free

[Kekun]

Without this, GNOME Weather is considered to be proprietary by GNOME
Software.

[ximion]

This data is auto-generated from SPDX data, and the free-ness is derived from whether a license is considered "free" by OSI or the FSF.
According to the source data, this is not the case: https://github.com/spdx/license-list-data/blob/master/json/licenses.json#L2794
I don't want to hack around the auto-generated in AppStream, rather SPDX should add a merked that the license is open-source, or the FSF or OSI should just approve the license.
Given that the CC licenses are not for code, I actually wonder though whether the license for GNOME Weather is set correctly - project_license should only be for code and shouldn't include the documentation license (if the source code is really CC licensed, then that's correct of course).

[pwithnall]

Given that the CC licenses are not for code, I actually wonder though whether the license for GNOME Weather is set correctly - project_license should only be for code and shouldn't include the documentation license (if the source code is really CC licensed, then that's correct of course).

This looks like #312 / https://tecnocode.co.uk/2021/07/05/dont-generally-put-cc-by-sa-in-appdata/

[ximion]

I really don't think this is the solution - I will probably augment the free-license-list by a list of licenses that are considered DFSG-free, as outlined in #357 (comment), that should also resolve this issue and still not make AppStream a legal-ish authority on what is free software and what is not.