flatpak: Build librest for Flatpak

Since librest is not included in the runtime anymore
build it explicitly in our Flatpak manifest.
1 job for wip/mlundblad/flatpak-build-librest in 9 minutes and 42 seconds (queued for 3 seconds)
latest
Status Name Job ID Coverage
  Test
passed flatpak #1399422
flatpak

00:09:42