steam: Fetch metadata via Grilo

Since GriloMedia now can use Steam plugin, use it to fetch metadata.

Covers are still fetched via SteamCover for now.
4 jobs for steam-grilo-metadata in 31 minutes and 26 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #244039
flatpak:app

00:22:30

 
  Test
passed #244040
flatpak:tests

00:08:26

 
  Review
passed #244041
review

00:00:29

manual #244042
allowed to fail manual
stop_review