Use 'fedora-all' instead of hardcoded targets

Signed-off-by: Frantisek Lachman <flachman@redhat.com>
4 jobs for test_case_simple in 0 seconds (queued for 1140 minutes and 26 seconds)
latest
Status Name Job ID Coverage
  External
passed packit-stg/rpm-build-fedora-31-x86_64

passed packit-stg/rpm-build-fedora-32-x86_64

passed packit-stg/rpm-build-fedora-33-x86_64

passed packit-stg/rpm-build-fedora-rawhide-x86_64