gitlab: use custom docker:dind image

The current docker:dind container has broken default seccomp filter that
results in clone3 being blocked, which in turn breaks Fedora 35 rawhide.

This custom image has a workaround that causes the seccomp filter to
return ENOSYS for clone3 instad of EPERM, thus triggering glibc to
fallback to clone correctly.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
8 jobs for master in 6 minutes and 25 seconds (queued for 3 seconds)
Status Name Job ID Coverage
  Containers
passed x64-centos-7-container #1469230424

00:01:14

passed x64-fedora-32-container #1469230459

00:01:18

passed x64-fedora-33-container #1469230464

00:01:30

passed x64-fedora-rawhide-container #1469230467

00:01:17

 
  Builds
passed x64-centos-7-git-build #1469230468

00:04:54

passed x64-fedora-32-dist-build #1469230478

00:02:28

passed x64-fedora-33-dist-build #1469230485

00:02:42

passed x64-fedora-rawhide-dist-build #1469230487

00:03:11