Fix license of KSyntaxHighlighting

[cornelius]

The license of KSyntaxHighlighting is shown as LGPL2.1+ (https://github.com/cornelius/inqlude-data/blob/master/syntax-highlighting/syntax-highlighting.manifest#L15). It should actually be MIT (https://invent.kde.org/frameworks/syntax-highlighting#licensing).

This is an artifact of the automatic import of KDE Frameworks, which assumes that all frameworks are under the same license (https://github.com/cornelius/inqlude/blob/master/lib/kde_frameworks_creator.rb#L202).

One solution would be to add a license field to the metainfo.yaml file (https://invent.kde.org/frameworks/syntax-highlighting/-/blob/master/metainfo.yaml) and parse that when creating the release manifests for KDE Frameworks. It still could default to LGPL2.1+, if not present, so that only frameworks which have a different license need to add it.