ci: update to more recent freedesktop/ci-templates is blocked

We use https://gitlab.freedesktop.org/freedesktop/ci-templates in .gitlab-ci.yml and we're pinning to ref freedesktop/ci-templates@16bc2907

After the following change "boot2container: bump to 0.9.9" freedesktop/ci-templates@c565e7a5 The job python-container would fail with the following message:

+ buildah run --isolation chroot debian-working-container-4 env DEBIAN_FRONTEND=noninteractive apt-get update
error running subprocess: creating new mount namespace for [/usr/bin/env DEBIAN_FRONTEND=noninteractive apt-get update]: operation not permitted

(from https://gitlab.freedesktop.org/ana/valve-infra/-/jobs/36423780#L165 )

We need to find out eventually why this is happening.