[neon-notifications] kdiagram new version 2.7.0

[Neon CI]

https://build.neon.kde.org/job/watcher_release_extras_kdiagram/723/display/redirect

#<Debian::UScan::DEHS::Package:0x0000555eb8715630 @name="kdiagram", @debian_uversion="2.6.3", @debian_mangled_uversion="2.6.3", @upstream_version="2.7.0", @upstream_url="http://download.kde.internal.neon.kde.org/stable/kdiagram/2.7.0/kdiagram-2.7.0.tar.xz", @status="Newer version available">