gitlab CI: bump to use Fedora 33

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2 jobs for wip/bump-ci in 3 minutes and 9 seconds (queued for 1 second)
Status Job ID Name Coverage
  Containers
passed fedora@container_build #8577979

00:02:30

 
  Build
passed fedora:33@default-build #8577980

00:00:38