Revert "ci: use stable fedora to fix ci"

GNOME CI runners have been updated to the latest libseccomp so the
problem should no longer happen.

This reverts commit f84e9a27.
4 jobs for master in 3 minutes and 49 seconds
Status Job ID Name Coverage
  Test
passed build_stable #1034624

00:03:27

passed build_tracker2 #1034625

00:03:47

failed build_stable #1034589

00:04:32

failed build_tracker2 #1034590

00:04:12