Fix org.kde.klimbgrades and org.kde.konversation-qtquick builds

Both pull in Kirigami master which requires Frameworks 5.38 (master),
when the runtime currently has 5.37 (stable). As Kirigami doesn't
-actually- depend on anything else in Frameworks master, patch its
sources to lower the KF5 version dependency.

A downside to this approach is that the patch and thus the build
will break again once Kirigami master flips to 5.39.