If unprivileged user namespaces are not allowed,
then integration tests with Docker DB on newer ubuntu versions will fail with "VM crashed".
See detailed description linked in "IntRef".

The current ticket therefor proposes to add this command to the template for workflow file slow-checks.yml.

      - name: Allow unprivileged user namespaces
        run: sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0