Embed JSON metadata in KIOSlaves

Task: https://phabricator.kde.org/T14518
2 jobs for master in 4 minutes and 51 seconds (queued for 9 minutes and 53 seconds)
Status Name Job ID Coverage
  Build
passed build_clazy_clang_tidy #109634

00:02:53

passed linux kf5-qt5 qt5.15 #109633

00:01:58

16.0%